fix: treat TLS config errors as permanent in both IMAP and JMAP sync loops

TlsModeMismatchException and TlsCertificateException now short-circuit
_isPermanentError() in both sync loop implementations, stopping the
retry loop immediately instead of hammering a misconfigured server.
Surfaces via the existing syncLastErrorProvider error banner.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

PLAN_ISSUE_21.md

@@ -0,0 +1,59 @@
+# Implementation Plan: Secure WebView for HTML Emails (#21)
+
+## Goal
+Replace the current `flutter_html` based rendering with a hardened WebView-based approach to improve rendering fidelity while strictly enforcing security and privacy.
+
+## 1. Dependency Management
+- **Core**: `webview_flutter` (v4+)
+- **Linux Platform**: `webview_flutter_linux` (Official community-supported or WebKitGTK based implementation). *Note: I will verify the exact package name during implementation.*
+- **Utilities**: `url_launcher` (existing) for opening links in the system browser.
+
+## 2. Secure WebView Component (`lib/ui/widgets/secure_email_webview.dart`)
+Create a new widget `SecureEmailWebView` that encapsulates the `WebViewWidget` and its controller.
+
+### Configuration & Hardening
+- **Disable JavaScript**: `controller.setJavaScriptMode(JavaScriptMode.disabled)`.
+- **Background**: Match the application theme (e.g., transparent or surface color).
+- **Security Headers/CSP**: Inject a Content Security Policy via `<meta>` tag in the HTML wrapper:
+  - `default-src 'none'; style-src 'unsafe-inline'; img-src 'self' data:;` (Blocks all external assets by default).
+
+### Image Blocking Logic
+- **Initial State**: Block remote images by injecting a CSP that restricts `img-src` to `data:` and local schemes.
+- **Toggle Mechanism**:
+  - Provide a "Load Remote Images" button in the Flutter UI.
+  - When triggered, re-render the HTML with an updated CSP: `img-src * data:;`.
+
+### Link Interception & Phishing Protection
+- Implement `NavigationDelegate.onNavigationRequest`.
+- **Process**:
+  1. Intercept any URL that doesn't start with `about:blank` or `data:`.
+  2. Block the navigation in the WebView.
+  3. Trigger a Flutter `showDialog` for confirmation.
+- **Phishing Protection Dialog**:
+  - Show the full URL.
+  - **Bold the FQDN**: Parse the URL using `Uri.parse`.
+    - Example: `https://`**`important-bank.com`**`/login`
+  - "Open in Browser" button uses `url_launcher`.
+
+## 3. Integration Plan
+### Step 1: Initialization
+Modify `lib/main.dart` to initialize the Linux WebView platform (using `webview_flutter_linux` or similar) during app startup.
+
+### Step 2: Replace Renderer in Screens
+- **EmailDetailScreen**: Replace `Html(...)` with `SecureEmailWebView(html: body.htmlBody!)`.
+- **ThreadDetailScreen**: Replace `Html(...)` with `SecureEmailWebView(html: body.htmlBody!)`.
+- Remove `flutter_html` imports and dependencies once migration is complete.
+
+## 4. Verification & Security Audit
+- **Manual Tests**:
+  - Open emails with complex HTML layouts.
+  - Verify images are blocked initially.
+  - Verify "Load images" works.
+  - Click various links (http, https, mailto) and verify the confirmation dialog and FQDN bolding.
+- **Security Check**:
+  - Verify that `<script>` tags are not executed.
+  - Verify no network requests for external images occur before user consent (via DevTools or proxy).
+
+## 5. Potential Challenges
+- **Linux WebView Stability**: WebKitGTK on Linux can sometimes have rendering or sizing issues in Flutter.
+- **Scrolling**: Ensuring the WebView integrates smoothly into the `ListView` of the email detail screen (might require fixed height or `SizedBox`).

Taskfile.yml

@@ -331,6 +331,12 @@ tasks:
     cmds:
       - fvm dart run scripts/check_coverage.dart
 
+  check-coverage:
+    desc: Run unit+widget tests with coverage, then fail if the gate is not met
+    deps: [test]
+    cmds:
+      - task: coverage
+
   website-dev:
     desc: Run Hugo development server
     cmds:
@@ -361,8 +367,8 @@ tasks:
           ${SSH_USER}@${SSH_HOST}:public_html/
 
   check-fast:
-    desc: Pre-commit checks — analyze + unit tests + widget tests (no build, no integration)
+    desc: Pre-commit checks — analyze + unit+widget tests + coverage gate (no build, no integration)
-    deps: [analyze, test, check-hygiene]
+    deps: [analyze, check-coverage, check-hygiene]
 
   check-hygiene:
     desc: Verify that no forbidden files (like home dir config) are tracked

android/app/build.gradle.kts

@@ -13,6 +13,7 @@ android {
     compileOptions {
         sourceCompatibility = JavaVersion.VERSION_17
         targetCompatibility = JavaVersion.VERSION_17
+        isCoreLibraryDesugaringEnabled = true
     }
 
     kotlinOptions {
@@ -65,6 +66,8 @@ flutter {
 }
 
 dependencies {
+    // Required for flutter_local_notifications and other plugins that need Java 8+ APIs on API < 26.
+    coreLibraryDesugaring("com.android.tools:desugar_jdk_libs:2.1.4")
     // integration_test is a dev dependency; the Flutter plugin loader adds it as
     // debugImplementation only, but GeneratedPluginRegistrant.java (in src/main)
     // references its class in all variants. Make it available for release compilation

flake.nix

@@ -84,6 +84,8 @@
             # python3 base + Google Play API client (for scripts/deploy_playstore.py)
             (python3.withPackages (ps: with ps; [
               google-api-python-client
+              google-auth-httplib2
+              httplib2
             ]))  # used by stalwart-dev/start and deploy_playstore.py
             fgj      # Codeberg/Forgejo CLI (like gh for GitHub)
           ]);

lib/core/repositories/email_repository.dart

@@ -1,14 +1,19 @@
 import 'package:sharedinbox/core/models/email.dart';
 
 abstract class EmailRepository {
-  Stream<List<Email>> observeEmails(String accountId, String mailboxPath);
+  Stream<List<Email>> observeEmails(
+    String accountId,
+    String mailboxPath, {
+    int limit = 50,
+  });
 
   /// Groups emails by threadId and returns one [EmailThread] per thread,
   /// sorted by the latest message date descending.
   Stream<List<EmailThread>> observeThreads(
     String accountId,
-    String mailboxPath,
+    String mailboxPath, {
-  );
+    int limit = 50,
+  });
 
   /// Returns all emails belonging to [threadId] in [mailboxPath].
   Stream<List<Email>> observeEmailsInThread(

lib/core/sync/account_sync_manager.dart

@@ -11,6 +11,7 @@ import 'package:sharedinbox/core/repositories/sync_log_repository.dart';
 import 'package:sharedinbox/core/utils/logger.dart';
 import 'package:sharedinbox/data/imap/imap_client_factory.dart'
     show ImapConnectFn, connectImap, verboseLogKey;
+import 'package:sharedinbox/data/imap/tls_error.dart' show isTlsConfigError;
 
 typedef OnNewMailCallback = Future<void> Function(String accountEmail);
 
@@ -291,6 +292,7 @@ class _AccountSync implements _SyncLoop {
   }
 
   bool _isPermanentError(Object e) {
+    if (isTlsConfigError(e)) return true;
     final s = e.toString().toLowerCase();
     // enough_mail doesn't always have typed exceptions for auth, so we check strings.
     return s.contains('invalid credentials') ||
@@ -528,6 +530,7 @@ class _JmapAccountSync implements _SyncLoop {
   }
 
   bool _isPermanentError(Object e) {
+    if (isTlsConfigError(e)) return true;
     final s = e.toString().toLowerCase();
     return s.contains('invalid credentials') ||
         s.contains('authentication failed') ||

lib/core/sync/background_sync.dart

@@ -38,7 +38,7 @@ Future<void> registerBackgroundSync() async {
     _kTaskName,
     frequency: const Duration(minutes: 15),
     constraints: Constraints(networkType: NetworkType.connected),
-    existingWorkPolicy: ExistingWorkPolicy.keep,
+    existingWorkPolicy: ExistingPeriodicWorkPolicy.keep,
   );
 }
 

lib/data/db/database.dart

@@ -269,10 +269,47 @@ class AppDatabase extends _$AppDatabase {
   AppDatabase([QueryExecutor? executor]) : super(executor ?? _openConnection());
 
   @override
-  int get schemaVersion => 24;
+  int get schemaVersion => 26;
+
+  Future<void> _createEmailFts() async {
+    await customStatement('''
+      CREATE VIRTUAL TABLE IF NOT EXISTS email_fts USING fts5(
+        subject, preview, from_json,
+        content='emails',
+        content_rowid='rowid'
+      )
+    ''');
+    await customStatement('''
+      CREATE TRIGGER IF NOT EXISTS email_fts_ai
+      AFTER INSERT ON emails BEGIN
+        INSERT INTO email_fts(rowid, subject, preview, from_json)
+        VALUES (new.rowid, new.subject, new.preview, new.from_json);
+      END
+    ''');
+    await customStatement('''
+      CREATE TRIGGER IF NOT EXISTS email_fts_au
+      AFTER UPDATE OF subject, preview, from_json ON emails BEGIN
+        INSERT INTO email_fts(email_fts, rowid, subject, preview, from_json)
+        VALUES ('delete', old.rowid, old.subject, old.preview, old.from_json);
+        INSERT INTO email_fts(rowid, subject, preview, from_json)
+        VALUES (new.rowid, new.subject, new.preview, new.from_json);
+      END
+    ''');
+    await customStatement('''
+      CREATE TRIGGER IF NOT EXISTS email_fts_ad
+      AFTER DELETE ON emails BEGIN
+        INSERT INTO email_fts(email_fts, rowid, subject, preview, from_json)
+        VALUES ('delete', old.rowid, old.subject, old.preview, old.from_json);
+      END
+    ''');
+  }
 
   @override
   MigrationStrategy get migration => MigrationStrategy(
+        onCreate: (m) async {
+          await m.createAll();
+          await _createEmailFts();
+        },
         onUpgrade: (m, from, to) async {
           // NOTE: m.createTable(T) creates the LATEST version of table T.
           // If you later add a column C to T in version X, you must guard
@@ -431,6 +468,30 @@ class AppDatabase extends _$AppDatabase {
           if (from >= 4 && from < 24) {
             await m.addColumn(drafts, drafts.imapServerId);
           }
+          if (from < 25) {
+            // For observeMailboxes: filter by account_id, sort by path.
+            await m.createIndex(
+              Index(
+                'mailboxes_account_id',
+                'CREATE INDEX IF NOT EXISTS mailboxes_account_id ON mailboxes (account_id, path);',
+              ),
+            );
+            // For observeThreads: filter by account_id+mailbox_path, sort by latest_date.
+            await m.createIndex(
+              Index(
+                'threads_latest_date',
+                'CREATE INDEX IF NOT EXISTS threads_latest_date ON threads (account_id, mailbox_path, latest_date DESC);',
+              ),
+            );
+          }
+          if (from < 26) {
+            await _createEmailFts();
+            // Backfill FTS index from existing rows.
+            await customStatement('''
+              INSERT INTO email_fts(rowid, subject, preview, from_json)
+              SELECT rowid, subject, preview, from_json FROM emails
+            ''');
+          }
         },
       );
 }

lib/data/imap/tls_error.dart

@@ -21,15 +21,52 @@ class TlsModeMismatchException implements Exception {
       'STARTTLS). Original error: $original';
 }
 
-/// If [error] is a TLS handshake failure caused by a wrong-version-number
+/// Wraps a TLS certificate verification failure into a user-actionable message.
-/// (i.e. the server is not speaking TLS), throw a [TlsModeMismatchException]
+///
-/// with [host]/[port] context. Otherwise rethrow [error] unchanged.
+/// Thrown when the server's certificate cannot be verified — either because it
+/// is self-signed, expired, or the CA chain has changed since the account was
+/// set up.
+class TlsCertificateException implements Exception {
+  TlsCertificateException(this.host, this.port, this.original);
+  final String host;
+  final int port;
+  final Object original;
+
+  @override
+  String toString() =>
+      'TLS certificate error on $host:$port — the server certificate could '
+      'not be verified. The certificate may have changed or expired. '
+      'Please re-check your account settings or contact your mail provider. '
+      'Original error: $original';
+}
+
+/// Returns true if [error] is a permanent TLS configuration error that will
+/// not resolve on its own and requires user action.
+bool isTlsConfigError(Object error) =>
+    error is TlsModeMismatchException || error is TlsCertificateException;
+
+/// If [error] is a recognisable TLS handshake failure, wraps it in a typed
+/// exception and throws it.  Otherwise rethrows [error] unchanged.
+///
+/// Recognised patterns:
+/// - `WRONG_VERSION_NUMBER` → [TlsModeMismatchException] (port/mode mismatch)
+/// - `CERTIFICATE_VERIFY_FAILED` / `HandshakeException` → [TlsCertificateException]
 Never rethrowAsTlsHint(Object error, StackTrace stack, String host, int port) {
-  if (error.toString().contains('WRONG_VERSION_NUMBER')) {
+  final s = error.toString();
+  if (s.contains('WRONG_VERSION_NUMBER')) {
     Error.throwWithStackTrace(
       TlsModeMismatchException(host, port, error),
       stack,
     );
   }
+  if (s.contains('CERTIFICATE_VERIFY_FAILED') ||
+      s.contains('HandshakeException') ||
+      s.contains('CERTIFICATE_EXPIRED') ||
+      s.contains('CERTIFICATE_UNKNOWN')) {
+    Error.throwWithStackTrace(
+      TlsCertificateException(host, port, error),
+      stack,
+    );
+  }
   Error.throwWithStackTrace(error, stack);
 }

lib/data/repositories/email_repository_impl.dart

@@ -58,15 +58,17 @@ class EmailRepositoryImpl implements EmailRepository {
   @override
   Stream<List<model.Email>> observeEmails(
     String accountId,
-    String mailboxPath,
+    String mailboxPath, {
-  ) {
+    int limit = 50,
+  }) {
     return (_db.select(_db.emails)
           ..where(
             (t) =>
                 t.accountId.equals(accountId) &
                 t.mailboxPath.equals(mailboxPath),
           )
-          ..orderBy([(t) => OrderingTerm.desc(t.receivedAt)]))
+          ..orderBy([(t) => OrderingTerm.desc(t.receivedAt)])
+          ..limit(limit))
         .watch()
         .map((rows) => rows.map(_toModel).toList());
   }
@@ -74,15 +76,17 @@ class EmailRepositoryImpl implements EmailRepository {
   @override
   Stream<List<model.EmailThread>> observeThreads(
     String accountId,
-    String mailboxPath,
+    String mailboxPath, {
-  ) {
+    int limit = 50,
+  }) {
     return (_db.select(_db.threads)
           ..where(
             (t) =>
                 t.accountId.equals(accountId) &
                 t.mailboxPath.equals(mailboxPath),
           )
-          ..orderBy([(t) => OrderingTerm.desc(t.latestDate)]))
+          ..orderBy([(t) => OrderingTerm.desc(t.latestDate)])
+          ..limit(limit))
         .watch()
         .map((rows) => rows.map(_threadRowToModel).toList());
   }
@@ -2470,28 +2474,39 @@ class EmailRepositoryImpl implements EmailRepository {
     String? accountId,
     String query,
   ) async {
+    final ftsQuery = _toFtsQuery(query);
+    if (ftsQuery.isEmpty) return [];
+
+    final sql = accountId != null
+        ? 'SELECT e.* FROM email_fts f JOIN emails e ON e.rowid = f.rowid'
+            ' WHERE email_fts MATCH ? AND e.account_id = ? ORDER BY rank LIMIT 50'
+        : 'SELECT e.* FROM email_fts f JOIN emails e ON e.rowid = f.rowid'
+            ' WHERE email_fts MATCH ? ORDER BY rank LIMIT 50';
+    final variables = accountId != null
+        ? [Variable<String>(ftsQuery), Variable<String>(accountId)]
+        : [Variable<String>(ftsQuery)];
+
+    final queryRows = await _db
+        .customSelect(sql, variables: variables, readsFrom: {_db.emails}).get();
+    final emailRows = await Future.wait(
+      queryRows.map((r) => _db.emails.mapFromRow(r)),
+    );
+    return emailRows.map(_toModel).toList();
+  }
+
+  /// Converts a user query string into an FTS5 match expression.
+  /// Each whitespace-separated word becomes a prefix term (word*) so that
+  /// partial words still match. Special FTS5 characters are stripped.
+  static String _toFtsQuery(String query) {
     final words = query
-        .toLowerCase()
+        .trim()
         .split(RegExp(r'\s+'))
         .where((w) => w.isNotEmpty)
+        .map((w) => w.replaceAll(RegExp(r'[^\w]'), ''))
+        .where((w) => w.isNotEmpty)
         .toList();
-    final rows = await (_db.select(_db.emails)
+    if (words.isEmpty) return '';
-          ..where((t) {
+    return words.map((w) => '$w*').join(' ');
-            Expression<bool> condition = const Constant(true);
-            if (accountId != null) {
-              condition = t.accountId.equals(accountId);
-            }
-            for (final word in words) {
-              final pattern = '%$word%';
-              condition = condition &
-                  (t.subject.like(pattern) | t.preview.like(pattern));
-            }
-            return condition;
-          })
-          ..orderBy([(t) => OrderingTerm.desc(t.receivedAt)])
-          ..limit(50))
-        .get();
-    return rows.map(_toModel).toList();
   }
 
   @override

lib/di.dart

@@ -3,6 +3,7 @@ import 'dart:async';
 import 'package:flutter_riverpod/flutter_riverpod.dart';
 import 'package:http/http.dart' as http;
 import 'package:sharedinbox/core/models/account.dart' as model;
+import 'package:sharedinbox/core/models/email.dart';
 import 'package:sharedinbox/core/models/undo_action.dart';
 import 'package:sharedinbox/core/repositories/account_repository.dart';
 import 'package:sharedinbox/core/repositories/draft_repository.dart';
@@ -17,7 +18,7 @@ import 'package:sharedinbox/core/services/undo_service.dart';
 import 'package:sharedinbox/core/storage/secure_storage.dart';
 import 'package:sharedinbox/core/sync/account_sync_manager.dart';
 import 'package:sharedinbox/core/sync/reliability_runner.dart';
-import 'package:sharedinbox/data/db/database.dart';
+import 'package:sharedinbox/data/db/database.dart' hide Email, EmailBody;
 import 'package:sharedinbox/data/imap/imap_client_factory.dart';
 import 'package:sharedinbox/data/jmap/sieve_repository.dart';
 import 'package:sharedinbox/data/repositories/account_repository_impl.dart';
@@ -168,6 +169,27 @@ final undoServiceProvider =
   return service;
 });
 
+/// Loads email header + body and marks the email as seen.
+/// Owned by [EmailDetailScreen]; decouples data loading from the widget tree.
+final emailDetailProvider = AsyncNotifierProvider.autoDispose
+    .family<EmailDetailNotifier, (Email?, EmailBody), String>(
+  EmailDetailNotifier.new,
+);
+
+class EmailDetailNotifier
+    extends AutoDisposeFamilyAsyncNotifier<(Email?, EmailBody), String> {
+  @override
+  Future<(Email?, EmailBody)> build(String emailId) async {
+    final repo = ref.read(emailRepositoryProvider);
+    final results = await Future.wait([
+      repo.getEmail(emailId),
+      repo.getEmailBody(emailId),
+    ]);
+    unawaited(repo.setFlag(emailId, seen: true));
+    return (results[0] as Email?, results[1] as EmailBody);
+  }
+}
+
 final accountByIdProvider =
     StreamProvider.autoDispose.family<model.Account?, String>((ref, accountId) {
   return ref.watch(accountRepositoryProvider).observeAccounts().map(

lib/ui/screens/email_detail_screen.dart

@@ -26,144 +26,130 @@ class EmailDetailScreen extends ConsumerStatefulWidget {
 }
 
 class _EmailDetailScreenState extends ConsumerState<EmailDetailScreen> {
-  late final Future<(Email?, EmailBody)> _dataFuture;
   bool _isFlagged = false;
   bool _loadRemoteImages = false;
   final Set<String> _downloading = {};
 
-  @override
-  void initState() {
-    super.initState();
-    final repo = ref.read(emailRepositoryProvider);
-    _dataFuture = Future.wait([
-      repo.getEmail(widget.emailId),
-      repo.getEmailBody(widget.emailId),
-    ]).then((results) {
-      final email = results[0] as Email?;
-      if (email != null && mounted) {
-        setState(() => _isFlagged = email.isFlagged);
-      }
-      return (email, results[1] as EmailBody);
-    });
-    unawaited(repo.setFlag(widget.emailId, seen: true));
-  }
-
   @override
   Widget build(BuildContext context) {
     final repo = ref.watch(emailRepositoryProvider);
-    return FutureBuilder<(Email?, EmailBody)>(
+    final detail = ref.watch(emailDetailProvider(widget.emailId));
-      future: _dataFuture,
-      builder: (ctx, snap) {
-        final header = snap.data?.$1;
-        final body = snap.data?.$2;
 
-        return Scaffold(
+    ref.listen<AsyncValue<(Email?, EmailBody)>>(
-          appBar: AppBar(
+      emailDetailProvider(widget.emailId),
-            title: Text(
+      (_, next) {
-              header?.subject ?? '(loading…)',
+        final email = next.valueOrNull?.$1;
-              overflow: TextOverflow.ellipsis,
+        if (email != null && mounted) {
+          setState(() => _isFlagged = email.isFlagged);
+        }
+      },
+    );
+
+    final header = detail.valueOrNull?.$1;
+    final body = detail.valueOrNull?.$2;
+
+    return Scaffold(
+      appBar: AppBar(
+        title: Text(
+          header?.subject ?? '(loading…)',
+          overflow: TextOverflow.ellipsis,
+        ),
+        actions: [
+          IconButton(
+            icon: const Icon(Icons.reply),
+            tooltip: 'Reply',
+            onPressed: header == null
+                ? null
+                : () => _reply(context, header, body, replyAll: false),
+          ),
+          IconButton(
+            icon: const Icon(Icons.reply_all),
+            tooltip: 'Reply all',
+            onPressed: header == null
+                ? null
+                : () => _reply(context, header, body, replyAll: true),
+          ),
+          IconButton(
+            icon: const Icon(Icons.forward),
+            tooltip: 'Forward',
+            onPressed:
+                header == null ? null : () => _forward(context, header, body),
+          ),
+          IconButton(
+            icon: const Icon(Icons.mark_email_unread_outlined),
+            tooltip: 'Mark as unread',
+            onPressed: () async {
+              await repo.setFlag(widget.emailId, seen: false);
+              if (context.mounted) context.pop();
+            },
+          ),
+          IconButton(
+            icon: Icon(
+              _isFlagged ? Icons.star : Icons.star_border,
+              color: _isFlagged ? Colors.amber : null,
             ),
-            actions: [
+            tooltip: _isFlagged ? 'Unflag' : 'Flag',
-              IconButton(
+            onPressed: () async {
-                icon: const Icon(Icons.reply),
+              final next = !_isFlagged;
-                tooltip: 'Reply',
+              await repo.setFlag(widget.emailId, flagged: next);
-                onPressed: header == null
+              if (mounted) setState(() => _isFlagged = next);
-                    ? null
+            },
-                    : () => _reply(context, header, body, replyAll: false),
+          ),
-              ),
+          IconButton(
-              IconButton(
+            icon: const Icon(Icons.drive_file_move_outline),
-                icon: const Icon(Icons.reply_all),
+            tooltip: 'Move to folder',
-                tooltip: 'Reply all',
+            onPressed: header == null ? null : () => _moveTo(context, header),
-                onPressed: header == null
+          ),
-                    ? null
+          IconButton(
-                    : () => _reply(context, header, body, replyAll: true),
+            icon: const Icon(Icons.access_time),
-              ),
+            tooltip: 'Snooze',
-              IconButton(
+            onPressed: header == null ? null : () => _snooze(context, header),
-                icon: const Icon(Icons.forward),
+          ),
-                tooltip: 'Forward',
+          IconButton(
-                onPressed: header == null
+            icon: const Icon(Icons.delete),
-                    ? null
+            tooltip: 'Delete',
-                    : () => _forward(context, header, body),
+            onPressed: () async {
-              ),
+              final destPath = await repo.deleteEmail(widget.emailId);
-              IconButton(
-                icon: const Icon(Icons.mark_email_unread_outlined),
-                tooltip: 'Mark as unread',
-                onPressed: () async {
-                  await repo.setFlag(widget.emailId, seen: false);
-                  if (context.mounted) context.pop();
-                },
-              ),
-              IconButton(
-                icon: Icon(
-                  _isFlagged ? Icons.star : Icons.star_border,
-                  color: _isFlagged ? Colors.amber : null,
-                ),
-                tooltip: _isFlagged ? 'Unflag' : 'Flag',
-                onPressed: () async {
-                  final next = !_isFlagged;
-                  await repo.setFlag(widget.emailId, flagged: next);
-                  if (mounted) setState(() => _isFlagged = next);
-                },
-              ),
-              IconButton(
-                icon: const Icon(Icons.drive_file_move_outline),
-                tooltip: 'Move to folder',
-                onPressed:
-                    header == null ? null : () => _moveTo(context, header),
-              ),
-              IconButton(
-                icon: const Icon(Icons.access_time),
-                tooltip: 'Snooze',
-                onPressed:
-                    header == null ? null : () => _snooze(context, header),
-              ),
-              IconButton(
-                icon: const Icon(Icons.delete),
-                tooltip: 'Delete',
-                onPressed: () async {
-                  final destPath = await repo.deleteEmail(widget.emailId);
 
-                  if (header != null) {
+              if (header != null) {
-                    unawaited(
+                unawaited(
-                      ref.read(undoServiceProvider.notifier).pushAction(
+                  ref.read(undoServiceProvider.notifier).pushAction(
-                            UndoAction(
+                        UndoAction(
-                              id: DateTime.now().toIso8601String(),
+                          id: DateTime.now().toIso8601String(),
-                              accountId: header.accountId,
+                          accountId: header.accountId,
-                              type: UndoType.delete,
+                          type: UndoType.delete,
-                              emailIds: [widget.emailId],
+                          emailIds: [widget.emailId],
-                              sourceMailboxPath: header.mailboxPath,
+                          sourceMailboxPath: header.mailboxPath,
-                              destinationMailboxPath: destPath,
+                          destinationMailboxPath: destPath,
-                              originalEmails: [header],
+                          originalEmails: [header],
-                            ),
+                        ),
-                          ),
+                      ),
-                    );
+                );
-                  }
+              }
 
-                  if (context.mounted) context.pop();
+              if (context.mounted) context.pop();
-                },
+            },
-              ),
+          ),
-              PopupMenuButton<String>(
+          PopupMenuButton<String>(
-                itemBuilder: (ctx) => [
+            itemBuilder: (ctx) => [
-                  const PopupMenuItem(
+              const PopupMenuItem(
-                    value: 'headers',
+                value: 'headers',
-                    child: Text('Show Mail Headers'),
+                child: Text('Show Mail Headers'),
-                  ),
-                ],
-                onSelected: (value) {
-                  if (value == 'headers' && body != null) {
-                    _showHeaders(context, body);
-                  }
-                },
               ),
             ],
+            onSelected: (value) {
+              if (value == 'headers' && body != null) {
+                _showHeaders(context, body);
+              }
+            },
           ),
-          body: snap.connectionState == ConnectionState.waiting
+        ],
-              ? const Center(child: CircularProgressIndicator())
+      ),
-              : snap.hasError
+      body: detail.when(
-                  ? Center(child: Text('Error: ${snap.error}'))
+        loading: () => const Center(child: CircularProgressIndicator()),
-                  : _buildBody(ctx, header, body!),
+        error: (e, _) => Center(child: Text('Error: $e')),
-        );
+        data: (d) => _buildBody(context, d.$1, d.$2),
-      },
+      ),
     );
   }
 
@@ -186,7 +172,7 @@ class _EmailDetailScreenState extends ConsumerState<EmailDetailScreen> {
                 ),
               ),
             ),
-          Html(
+          _SafeHtml(
             data: body.htmlBody!,
             extensions: [if (!_loadRemoteImages) _BlockRemoteImagesExtension()],
           ),
@@ -501,6 +487,57 @@ class _UnsubscribeChip extends StatelessWidget {
   }
 }
 
+/// Renders [Html] and falls back to an error message if the widget throws
+/// during build, preventing a malformed body from crashing the whole screen.
+class _SafeHtml extends StatefulWidget {
+  const _SafeHtml({required this.data, required this.extensions});
+  final String data;
+  final List<HtmlExtension> extensions;
+
+  @override
+  State<_SafeHtml> createState() => _SafeHtmlState();
+}
+
+class _SafeHtmlState extends State<_SafeHtml> {
+  bool _failed = false;
+
+  @override
+  Widget build(BuildContext context) {
+    if (_failed) {
+      return Padding(
+        padding: const EdgeInsets.all(8),
+        child: Row(
+          children: [
+            Icon(
+              Icons.warning_amber_outlined,
+              color: Theme.of(context).colorScheme.error,
+              size: 16,
+            ),
+            const SizedBox(width: 8),
+            const Expanded(child: Text('Message body could not be rendered.')),
+          ],
+        ),
+      );
+    }
+
+    // Intercept any build-phase throw from flutter_html for this subtree.
+    // We save/restore via postFrameCallback so other widgets are unaffected.
+    final prev = ErrorWidget.builder;
+    ErrorWidget.builder = (FlutterErrorDetails details) {
+      ErrorWidget.builder = prev;
+      WidgetsBinding.instance.addPostFrameCallback((_) {
+        if (mounted) setState(() => _failed = true);
+      });
+      return const SizedBox.shrink();
+    };
+    WidgetsBinding.instance.addPostFrameCallback(
+      (_) => ErrorWidget.builder = prev,
+    );
+
+    return Html(data: widget.data, extensions: widget.extensions);
+  }
+}
+
 class _BlockRemoteImagesExtension extends HtmlExtension {
   @override
   Set<String> get supportedTags => {'img'};

lib/ui/screens/email_list_screen.dart

@@ -10,6 +10,7 @@ import 'package:sharedinbox/core/models/email.dart';
 import 'package:sharedinbox/core/models/undo_action.dart';
 import 'package:sharedinbox/core/repositories/email_repository.dart';
 import 'package:sharedinbox/di.dart';
+import 'package:sharedinbox/ui/widgets/email_tile.dart';
 import 'package:sharedinbox/ui/widgets/folder_drawer.dart';
 import 'package:sharedinbox/ui/widgets/snooze_picker.dart';
 
@@ -44,6 +45,10 @@ class _EmailListScreenState extends ConsumerState<EmailListScreen> {
   List<EmailThread> _currentThreads = [];
   // Individual email selection used in search results.
   final Set<String> _selectedSearchIds = {};
+
+  // Pagination: number of threads currently requested from the DB.
+  static const _pageSize = 50;
+  int _limit = _pageSize;
   bool get _selecting =>
       _selectedThreadIds.isNotEmpty || _selectedSearchIds.isNotEmpty;
 
@@ -342,7 +347,11 @@ class _EmailListScreenState extends ConsumerState<EmailListScreen> {
         await emailRepo.syncEmails(widget.accountId, widget.mailboxPath);
       },
       child: StreamBuilder<List<EmailThread>>(
-        stream: emailRepo.observeThreads(widget.accountId, widget.mailboxPath),
+        stream: emailRepo.observeThreads(
+          widget.accountId,
+          widget.mailboxPath,
+          limit: _limit,
+        ),
         builder: (ctx, snap) {
           if (!snap.hasData) {
             return const Center(child: CircularProgressIndicator());
@@ -538,9 +547,16 @@ class _EmailListScreenState extends ConsumerState<EmailListScreen> {
   }
 
   Widget _buildThreadList(List<EmailThread> threads) {
+    final hasMore = threads.length == _limit;
     return ListView.builder(
-      itemCount: threads.length,
+      itemCount: threads.length + (hasMore ? 1 : 0),
       itemBuilder: (ctx, i) {
+        if (i == threads.length) {
+          return TextButton(
+            onPressed: () => setState(() => _limit += _pageSize),
+            child: const Text('Load more'),
+          );
+        }
         final t = threads[i];
         final isSelected = _selectedThreadIds.contains(t.threadId);
         final senderNames =
@@ -711,10 +727,9 @@ class _EmailListScreenState extends ConsumerState<EmailListScreen> {
       itemBuilder: (ctx, i) {
         final e = emails[i];
         final isSelected = _selectedSearchIds.contains(e.id);
-        final sender = e.from.isNotEmpty
+        return EmailTile(
-            ? (e.from.first.name ?? e.from.first.email)
+          email: e,
-            : '(unknown)';
+          selected: isSelected,
-        return ListTile(
           leading: SizedBox(
             width: 40,
             child: _selecting
@@ -722,25 +737,7 @@ class _EmailListScreenState extends ConsumerState<EmailListScreen> {
                     value: isSelected,
                     onChanged: (_) => _toggleSearchSelection(e.id),
                   )
-                : Icon(
+                : null,
-                    e.isSeen ? Icons.mail_outline : Icons.mail,
-                    color: e.isSeen ? null : Theme.of(ctx).colorScheme.primary,
-                  ),
-          ),
-          title: Text(
-            sender,
-            style:
-                e.isSeen ? null : const TextStyle(fontWeight: FontWeight.bold),
-          ),
-          subtitle: Text(
-            e.subject ?? '(no subject)',
-            maxLines: 1,
-            overflow: TextOverflow.ellipsis,
-          ),
-          selected: isSelected,
-          trailing: Text(
-            e.sentAt != null ? _dateFmt.format(e.sentAt!) : '',
-            style: Theme.of(ctx).textTheme.bodySmall,
           ),
           onTap: _selecting
               ? () => _toggleSearchSelection(e.id)

lib/ui/screens/search_screen.dart

@@ -8,6 +8,7 @@ import 'package:sharedinbox/core/models/email.dart';
 import 'package:sharedinbox/core/models/mailbox.dart';
 import 'package:sharedinbox/core/utils/logger.dart';
 import 'package:sharedinbox/di.dart';
+import 'package:sharedinbox/ui/widgets/email_tile.dart';
 
 class SearchScreen extends ConsumerStatefulWidget {
   const SearchScreen({super.key, this.accountId});
@@ -155,7 +156,15 @@ class _SearchScreenState extends ConsumerState<SearchScreen> {
         if (r.emails.isNotEmpty) ...[
           const _SectionHeader('Messages'),
           for (final e in r.emails)
-            _EmailTile(email: e, accountId: e.accountId),
+            EmailTile(
+              email: e,
+              showLocation: true,
+              onTap: () => context.push(
+                '/accounts/${e.accountId}/mailboxes'
+                '/${Uri.encodeComponent(e.mailboxPath)}'
+                '/emails/${Uri.encodeComponent(e.id)}',
+              ),
+            ),
         ],
       ],
     );
@@ -246,42 +255,3 @@ class _AddressTile extends StatelessWidget {
     );
   }
 }
-
-class _EmailTile extends StatelessWidget {
-  const _EmailTile({required this.email, required this.accountId});
-  final Email email;
-  final String accountId;
-
-  @override
-  Widget build(BuildContext context) {
-    final sender = email.from.isNotEmpty
-        ? (email.from.first.name ?? email.from.first.email)
-        : '(unknown)';
-    return ListTile(
-      leading: Icon(
-        email.isSeen ? Icons.mail_outline : Icons.mail,
-        color: email.isSeen ? null : Theme.of(context).colorScheme.primary,
-      ),
-      title: Text(sender),
-      subtitle: Column(
-        crossAxisAlignment: CrossAxisAlignment.start,
-        children: [
-          Text(
-            email.subject ?? '(no subject)',
-            maxLines: 1,
-            overflow: TextOverflow.ellipsis,
-          ),
-          Text(
-            '$accountId • ${email.mailboxPath}',
-            style: Theme.of(context).textTheme.bodySmall,
-          ),
-        ],
-      ),
-      onTap: () => context.push(
-        '/accounts/$accountId/mailboxes'
-        '/${Uri.encodeComponent(email.mailboxPath)}'
-        '/emails/${Uri.encodeComponent(email.id)}',
-      ),
-    );
-  }
-}

lib/ui/widgets/email_tile.dart

@@ -0,0 +1,74 @@
+import 'package:flutter/material.dart';
+import 'package:intl/intl.dart';
+
+import 'package:sharedinbox/core/models/email.dart';
+
+final _dateFmt = DateFormat('MMM d');
+
+/// A flat list tile for an individual [email].
+///
+/// Used in search-result lists and the per-mailbox search overlay.
+/// Pass a custom [leading] widget to support selection-mode checkboxes.
+class EmailTile extends StatelessWidget {
+  const EmailTile({
+    super.key,
+    required this.email,
+    required this.onTap,
+    this.leading,
+    this.selected = false,
+    this.onLongPress,
+    this.showLocation = false,
+  });
+
+  final Email email;
+  final VoidCallback onTap;
+  final Widget? leading;
+  final bool selected;
+  final VoidCallback? onLongPress;
+
+  /// When true, appends `accountId • mailboxPath` as a second subtitle line.
+  final bool showLocation;
+
+  @override
+  Widget build(BuildContext context) {
+    final sender = email.from.isNotEmpty
+        ? (email.from.first.name ?? email.from.first.email)
+        : '(unknown)';
+    final date = email.sentAt != null ? _dateFmt.format(email.sentAt!) : '';
+
+    return ListTile(
+      leading: leading ??
+          Icon(
+            email.isSeen ? Icons.mail_outline : Icons.mail,
+            color: email.isSeen ? null : Theme.of(context).colorScheme.primary,
+          ),
+      title: Text(
+        sender,
+        style:
+            email.isSeen ? null : const TextStyle(fontWeight: FontWeight.bold),
+        overflow: TextOverflow.ellipsis,
+      ),
+      subtitle: Column(
+        crossAxisAlignment: CrossAxisAlignment.start,
+        children: [
+          Text(
+            email.subject ?? '(no subject)',
+            maxLines: 1,
+            overflow: TextOverflow.ellipsis,
+          ),
+          if (showLocation)
+            Text(
+              '${email.accountId} • ${email.mailboxPath}',
+              style: Theme.of(context).textTheme.bodySmall,
+            ),
+        ],
+      ),
+      trailing: date.isEmpty
+          ? null
+          : Text(date, style: Theme.of(context).textTheme.bodySmall),
+      selected: selected,
+      onTap: onTap,
+      onLongPress: onLongPress,
+    );
+  }
+}

plan-claude.md

@@ -0,0 +1,159 @@
+# SharedInbox — Improvement Plan
+
+30 tasks across 7 perspectives. Priority markers: 🔴 high · 🟡 medium · 🟢 nice-to-have.
+
+---
+
+## Group 1: Performance
+
+### P1 — Done: https://codeberg.org/guettli/sharedinbox/pulls/41
+
+### P1 🔴 Replace LIKE-based search with FTS5 virtual table
+The current `observeEmails` and search queries use `LIKE '%query%'` which becomes a full-table scan at scale.
+Create an `email_fts` FTS5 virtual table (subject, preview, fromJson) populated via trigger or sync-time insert.
+Wire `SearchScreen` to query the FTS table instead.
+Files: `lib/data/db/database.dart`, `lib/data/repositories/email_repository_impl.dart`.
+
+### P2 🔴 Lazy-load email bodies on scroll (pagination)
+`observeThreads` and `observeEmails` return the full list with no limit. As the mailbox grows this streams thousands of rows into memory.
+Add a page-size parameter (e.g. 50) with "load more" support in `EmailListScreen`.
+The `EmailBodies` table is already separate — never fetch bodies in the list query.
+Files: `lib/data/repositories/email_repository_impl.dart`, `lib/ui/screens/email_list_screen.dart`.
+
+### P3 🟡 Defer HTML parsing off the UI thread using an Isolate
+`flutter_html` parsing blocks the raster thread for large HTML bodies, causing jank when opening email detail.
+Move the HTML→Widget tree conversion (or at minimum the `html_utils.dart` HTML-to-plain step) into a `compute()` call.
+Files: `lib/ui/screens/email_detail_screen.dart`, `lib/core/utils/html_utils.dart`.
+
+### P4 — Done: https://codeberg.org/guettli/sharedinbox/pulls/36
+
+### P5 🟢 Cache the formatted date strings in EmailListScreen
+`DateFormat('MMM d').format(...)` is called for every email on every rebuild. Compute and cache these in the model layer or inside the list item widget's `build` method using a static cache map.
+Files: `lib/ui/screens/email_list_screen.dart`, `lib/core/utils/format_utils.dart`.
+
+---
+
+## Group 2: Reliability & Resilience
+
+### R1 — Done: https://codeberg.org/guettli/sharedinbox/pulls/20
+
+### R2 — Done: https://codeberg.org/guettli/sharedinbox/pulls/22
+
+### R3 — Done: https://codeberg.org/guettli/sharedinbox/pulls/35
+
+### R4 — Done: https://codeberg.org/guettli/sharedinbox/pulls/23
+
+### R5 🟡 Handle TLS certificate changes gracefully
+`tls_error.dart` detects TLS errors but they bubble up as generic errors in the sync loop.
+Detect `TlsError` specifically in `_AccountSync` and show a user-facing dialog offering to re-add the account or trust the new certificate.
+Files: `lib/data/imap/tls_error.dart`, `lib/core/sync/account_sync_manager.dart`.
+
+### R6 — Done: https://codeberg.org/guettli/sharedinbox/pulls/24
+
+---
+
+## Group 3: Security
+
+### S1 🔴 Optional SQLCipher encryption for the Drift database
+Emails cached locally are plaintext. Users on shared or rooted devices are exposed.
+Add an opt-in "Encrypt local storage" setting using `drift`'s `encrypted` backend (`sqflite_cipher` / `sqlcipher_flutter_libs`).
+Store the database key in `flutter_secure_storage` (already present).
+Files: `lib/data/db/database.dart`, `pubspec.yaml`, a new settings toggle.
+
+### S2 — Done: https://codeberg.org/guettli/sharedinbox/pulls/25
+
+### S3 🟡 Enforce certificate pinning for known providers (opt-in)
+Auto-discovered accounts for major providers (Gmail, Fastmail, Proton) could be pinned to their known CA hierarchy.
+Implement as an opt-in per-account setting; only applies when the account is auto-discovered via `AccountDiscoveryService`.
+Files: `lib/core/services/account_discovery_service.dart`, `lib/data/imap/imap_client_factory.dart`.
+
+### S4 🟢 Audit and restrict external link handling in HTML emails
+`flutter_html` passes `<a href>` clicks to `url_launcher` without a prompt.
+Before launching, show a confirmation dialog with the destination URL so phishing links are visible.
+Files: `lib/ui/screens/email_detail_screen.dart`.
+
+---
+
+## Group 4: User Experience
+
+### U1 — Done: https://codeberg.org/guettli/sharedinbox/pulls/26
+
+### U2 — Done: https://codeberg.org/guettli/sharedinbox/pulls/27
+
+### U3 🟡 Add "Recent searches" history to SearchScreen
+The search bar clears on navigation. Store the last 10 search terms in a local DB table and show them as chips below the search field when the field is focused but empty.
+Files: `lib/ui/screens/search_screen.dart`, `lib/data/db/database.dart`.
+
+### U4 — Done: https://codeberg.org/guettli/sharedinbox/pulls/28
+
+### U5 — Already implemented (Dismissible archive/delete swipes with undo, found in email_list_screen.dart)
+
+### U6 — Done: https://codeberg.org/guettli/sharedinbox/pulls/29
+
+### U7 🟢 Onboarding walkthrough for first-time users
+The app opens directly to an empty account list with only a `+` button. First-time users have no guidance.
+Add a one-time welcome card or bottom-sheet with the three-step flow: Add account → wait for sync → open inbox.
+Files: `lib/ui/screens/account_list_screen.dart`.
+
+### U8 🟢 "Mark all as read" action in mailbox
+Power users managing high-volume mailboxes need bulk read marking. Add a "Mark all as read" option in the mailbox overflow menu.
+Files: `lib/ui/screens/email_list_screen.dart`, `lib/core/repositories/email_repository.dart`, `lib/data/repositories/email_repository_impl.dart`.
+
+---
+
+## Group 5: Testing
+
+### T1 — Done: https://codeberg.org/guettli/sharedinbox/pulls/30
+
+### T2 — Done: https://codeberg.org/guettli/sharedinbox/pulls/31
+
+### T3 🟡 Contract tests for all Repository interfaces
+The interfaces in `core/repositories/` have no shared contract test suite. Concrete impls can silently diverge.
+Add a shared `EmailRepositoryContract` abstract test class; run it against both `EmailRepositoryImpl` and any future mock/fake. Mirror this for `MailboxRepository` and `AccountRepository`.
+Files: `test/unit/` (new contract test files).
+
+### T4 — Done: https://codeberg.org/guettli/sharedinbox/pulls/32
+
+### T5 🟢 Snapshot / golden tests for key email list states
+The email list has multiple states: loading, empty, normal, selection mode, search active, error banner.
+Add golden tests using `matchesGoldenFile` for each state so visual regressions surface in CI.
+Files: `test/widget/email_list_screen_test.dart`.
+
+---
+
+## Group 6: Architecture & Code Quality
+
+### A1 — Done: https://codeberg.org/guettli/sharedinbox/pulls/39
+
+### A2 — Done: https://codeberg.org/guettli/sharedinbox/pulls/33
+
+### A3 🟡 Make AccountSyncManager testable without real IMAP connections
+`AccountSyncManager` accepts `ImapConnectFn` as a dependency but `_JmapAccountSync` constructs its HTTP client internally.
+Pass an injectable `http.Client` to `_JmapAccountSync` (already done in `EmailRepositoryImpl`; mirror the pattern here).
+Files: `lib/core/sync/account_sync_manager.dart`, `test/unit/account_sync_manager_test.dart`.
+
+### A4 🟡 Replace raw JSON strings in DB with structured encoding
+`fromJson`, `toAddresses`, `ccJson`, `references` are stored as raw JSON strings parsed on every model conversion.
+Create typed value classes with `fromJson`/`toJson` in `core/models/email.dart` and add a `TypeConverter` in the Drift schema so the DB layer owns the serialisation.
+Files: `lib/data/db/database.dart`, `lib/core/models/email.dart`, `lib/data/repositories/email_repository_impl.dart`.
+
+### A5 🟢 Enforce layer boundaries via lint custom rules or barrel imports
+The `ui/` layer directly imports `data/` concrete classes in several screens (e.g. `drift` types leak through).
+Add a custom `analysis_options.yaml` rule or a CI lint step that flags any `ui/` import of `data/` (only `core/` interfaces are allowed from UI).
+Files: `analysis_options.yaml`, CI config.
+
+---
+
+## Group 7: Developer Experience
+
+### D1 🔴 CI matrix for macOS and Windows builds
+The CI currently tests Linux and Android. The macOS and Windows targets are "scaffolded" and may have accumulated silent breakage.
+Add `flutter build macos --debug` and `flutter build windows --debug` jobs to the CI workflow with the same failure threshold as Linux.
+Files: `.github/workflows/ci.yml` (or Codeberg equivalent).
+
+### D2 — Done: https://codeberg.org/guettli/sharedinbox/pulls/34
+
+### D3 🟢 Document the sync protocol in a SYNC.md architecture doc
+`DB-SYNC.md` exists but focuses on the DB schema. The IMAP IDLE loop, exponential backoff, pending-change queue, and undo cancel logic are spread across four files with no single reference.
+Write `SYNC.md` that describes the full lifecycle of an email action from UI tap to server confirmation.
+Files: `SYNC.md` (new).

pubspec.yaml

@@ -47,7 +47,7 @@ dependencies:
 
   # Background sync and local notifications
   flutter_local_notifications: ^18.0.1
-  workmanager: ^0.5.2
+  workmanager: ^0.9.0
 
 dev_dependencies:
   flutter_test:

scripts/deploy_playstore.py

@@ -4,7 +4,10 @@
 import json
 import os
 import sys
+import time
 
+import google_auth_httplib2
+import httplib2
 from google.oauth2 import service_account
 from googleapiclient.discovery import build
 from googleapiclient.http import MediaFileUpload
@@ -12,6 +15,15 @@ from googleapiclient.http import MediaFileUpload
 PACKAGE_NAME = "de.sharedinbox.mua"
 AAB_PATH = "build/app/outputs/bundle/release/app-release.aab"
 TRACK = "internal"
+_TIMEOUT = 300  # seconds — AAB uploads can be large
+_MAX_UPLOAD_ATTEMPTS = 3
+
+
+def _make_service(creds):
+    authorized_http = google_auth_httplib2.AuthorizedHttp(
+        creds, http=httplib2.Http(timeout=_TIMEOUT)
+    )
+    return build("androidpublisher", "v3", http=authorized_http)
 
 
 def main():
@@ -29,19 +41,43 @@ def main():
         scopes=["https://www.googleapis.com/auth/androidpublisher"],
     )
 
-    service = build("androidpublisher", "v3", credentials=creds)
+    service = _make_service(creds)
 
-    edit = service.edits().insert(body={}, packageName=PACKAGE_NAME).execute()
+    edit = service.edits().insert(body={}, packageName=PACKAGE_NAME).execute(num_retries=3)
     edit_id = edit["id"]
 
-    media = MediaFileUpload(AAB_PATH, mimetype="application/octet-stream", resumable=True)
+    # The resumable upload can fail with RedirectMissingLocation on transient
-    bundle = (
+    # network hiccups. Retry the upload (with a fresh MediaFileUpload each
-        service.edits()
+    # time) using exponential backoff before giving up.
-        .bundles()
+    version_code = None
-        .upload(packageName=PACKAGE_NAME, editId=edit_id, media_body=media)
+    last_exc = None
-        .execute()
+    for attempt in range(_MAX_UPLOAD_ATTEMPTS):
-    )
+        try:
-    version_code = bundle["versionCode"]
+            media = MediaFileUpload(
+                AAB_PATH, mimetype="application/octet-stream", resumable=True
+            )
+            bundle = (
+                service.edits()
+                .bundles()
+                .upload(packageName=PACKAGE_NAME, editId=edit_id, media_body=media)
+                .execute(num_retries=3)
+            )
+            version_code = bundle["versionCode"]
+            break
+        except httplib2.error.RedirectMissingLocation as exc:
+            last_exc = exc
+            if attempt < _MAX_UPLOAD_ATTEMPTS - 1:
+                delay = 10 * (2 ** attempt)
+                print(
+                    f"Upload attempt {attempt + 1} failed (redirect error), "
+                    f"retrying in {delay}s…"
+                )
+                time.sleep(delay)
+    else:
+        raise RuntimeError(
+            f"AAB upload failed after {_MAX_UPLOAD_ATTEMPTS} attempts"
+        ) from last_exc
+
     print(f"Uploaded AAB, version code: {version_code}")
 
     service.edits().tracks().update(
@@ -49,9 +85,9 @@ def main():
         editId=edit_id,
         track=TRACK,
         body={"releases": [{"versionCodes": [version_code], "status": "completed"}]},
-    ).execute()
+    ).execute(num_retries=3)
 
-    service.edits().commit(packageName=PACKAGE_NAME, editId=edit_id).execute()
+    service.edits().commit(packageName=PACKAGE_NAME, editId=edit_id).execute(num_retries=3)
     print(f"Deployed version {version_code} to {TRACK} track")
 
 

test/integration/account_sync_manager_test.dart

@@ -105,10 +105,19 @@ class _FakeEmails implements EmailRepository {
   final syncCounts = <String, int>{};
 
   @override
-  Stream<List<Email>> observeEmails(String a, String m) => Stream.value([]);
+  Stream<List<Email>> observeEmails(
+    String a,
+    String m, {
+    int limit = 50,
+  }) =>
+      Stream.value([]);
 
   @override
-  Stream<List<EmailThread>> observeThreads(String a, String m) =>
+  Stream<List<EmailThread>> observeThreads(
+    String a,
+    String m, {
+    int limit = 50,
+  }) =>
       Stream.value([]);
 
   @override

test/unit/account_repository_contract_test.dart

@@ -0,0 +1,107 @@
+import 'package:flutter_test/flutter_test.dart';
+
+import 'package:sharedinbox/core/models/account.dart';
+import 'package:sharedinbox/core/repositories/account_repository.dart';
+import 'package:sharedinbox/data/repositories/account_repository_impl.dart';
+
+import 'account_repository_impl_test.dart' show MapSecureStorage;
+import 'db_test_helper.dart';
+
+// ── Contract ──────────────────────────────────────────────────────────────────
+
+/// Verifies the [AccountRepository] interface contract.
+///
+/// Subclass this and override [makeRepo] to run the same suite against any
+/// concrete implementation.
+abstract class AccountRepositoryContract {
+  AccountRepository makeRepo();
+
+  static const _a = Account(
+    id: 'c-1',
+    displayName: 'Contract',
+    email: 'c@example.com',
+    imapHost: 'imap.example.com',
+    smtpHost: 'smtp.example.com',
+  );
+
+  void run() {
+    test('observeAccounts starts empty', () async {
+      final repo = makeRepo();
+      expect(await repo.observeAccounts().first, isEmpty);
+    });
+
+    test('addAccount makes account visible via observeAccounts', () async {
+      final repo = makeRepo();
+      await repo.addAccount(_a, 'pw');
+      final list = await repo.observeAccounts().first;
+      expect(list, hasLength(1));
+      expect(list.first.id, _a.id);
+    });
+
+    test('getAccount returns null for unknown id', () async {
+      final repo = makeRepo();
+      expect(await repo.getAccount('no-such'), isNull);
+    });
+
+    test('getAccount returns added account', () async {
+      final repo = makeRepo();
+      await repo.addAccount(_a, 'pw');
+      final a = await repo.getAccount(_a.id);
+      expect(a, isNotNull);
+      expect(a!.email, _a.email);
+    });
+
+    test('getPassword returns stored password', () async {
+      final repo = makeRepo();
+      await repo.addAccount(_a, 'secret123');
+      expect(await repo.getPassword(_a.id), 'secret123');
+    });
+
+    test('updateAccount reflects changes in observeAccounts', () async {
+      final repo = makeRepo();
+      await repo.addAccount(_a, 'pw');
+      final updated = _a.copyWith(displayName: 'Updated');
+      await repo.updateAccount(updated);
+      final list = await repo.observeAccounts().first;
+      expect(list.first.displayName, 'Updated');
+    });
+
+    test('updateAccount with password updates stored password', () async {
+      final repo = makeRepo();
+      await repo.addAccount(_a, 'old');
+      await repo.updateAccount(_a, password: 'new');
+      expect(await repo.getPassword(_a.id), 'new');
+    });
+
+    test('removeAccount makes account disappear from observeAccounts',
+        () async {
+      final repo = makeRepo();
+      await repo.addAccount(_a, 'pw');
+      await repo.removeAccount(_a.id);
+      expect(await repo.observeAccounts().first, isEmpty);
+    });
+
+    test('getAccount returns null after removeAccount', () async {
+      final repo = makeRepo();
+      await repo.addAccount(_a, 'pw');
+      await repo.removeAccount(_a.id);
+      expect(await repo.getAccount(_a.id), isNull);
+    });
+  }
+}
+
+// ── Impl under test ───────────────────────────────────────────────────────────
+
+class _AccountRepositoryImplContract extends AccountRepositoryContract {
+  @override
+  AccountRepository makeRepo() =>
+      AccountRepositoryImpl(openTestDatabase(), MapSecureStorage());
+}
+
+void main() {
+  setUpAll(configureSqliteForTests);
+
+  group('AccountRepositoryImpl satisfies AccountRepository contract', () {
+    _AccountRepositoryImplContract().run();
+  });
+}

test/unit/account_sync_manager_test.dart

@@ -34,9 +34,18 @@ void main() {
 
 class FakeEmailRepository implements EmailRepository {
   @override
-  Stream<List<Email>> observeEmails(String a, String m) => Stream.value([]);
+  Stream<List<Email>> observeEmails(
+    String a,
+    String m, {
+    int limit = 50,
+  }) =>
+      Stream.value([]);
   @override
-  Stream<List<EmailThread>> observeThreads(String a, String m) =>
+  Stream<List<EmailThread>> observeThreads(
+    String a,
+    String m, {
+    int limit = 50,
+  }) =>
       Stream.value([]);
   @override
   Stream<List<Email>> observeEmailsInThread(String a, String m, String t) =>

test/unit/account_sync_manager_test.mocks.dart

@@ -215,9 +215,10 @@ class MockEmailRepository extends _i1.Mock implements _i9.EmailRepository {
 
   @override
   _i4.Stream<List<_i2.Email>> observeEmails(
-    String? accountId,
+    String accountId,
-    String? mailboxPath,
+    String mailboxPath, {
-  ) =>
+    int limit = 50,
+  }) =>
       (super.noSuchMethod(
         Invocation.method(
           #observeEmails,
@@ -225,15 +226,17 @@ class MockEmailRepository extends _i1.Mock implements _i9.EmailRepository {
             accountId,
             mailboxPath,
           ],
+          {#limit: limit},
         ),
         returnValue: _i4.Stream<List<_i2.Email>>.empty(),
       ) as _i4.Stream<List<_i2.Email>>);
 
   @override
   _i4.Stream<List<_i2.EmailThread>> observeThreads(
-    String? accountId,
+    String accountId,
-    String? mailboxPath,
+    String mailboxPath, {
-  ) =>
+    int limit = 50,
+  }) =>
       (super.noSuchMethod(
         Invocation.method(
           #observeThreads,
@@ -241,6 +244,7 @@ class MockEmailRepository extends _i1.Mock implements _i9.EmailRepository {
             accountId,
             mailboxPath,
           ],
+          {#limit: limit},
         ),
         returnValue: _i4.Stream<List<_i2.EmailThread>>.empty(),
       ) as _i4.Stream<List<_i2.EmailThread>>);

test/unit/email_repository_contract_test.dart

@@ -0,0 +1,193 @@
+import 'package:drift/drift.dart' show Value;
+import 'package:enough_mail/enough_mail.dart' as imap;
+import 'package:flutter_test/flutter_test.dart';
+
+import 'package:sharedinbox/core/models/account.dart';
+import 'package:sharedinbox/core/repositories/email_repository.dart';
+import 'package:sharedinbox/data/db/database.dart' hide Account;
+import 'package:sharedinbox/data/repositories/account_repository_impl.dart';
+import 'package:sharedinbox/data/repositories/email_repository_impl.dart';
+
+import 'account_repository_impl_test.dart' show MapSecureStorage;
+import 'db_test_helper.dart';
+
+// ── Contract ──────────────────────────────────────────────────────────────────
+
+/// Verifies the observable / local-state portion of the [EmailRepository]
+/// interface contract.
+///
+/// Network-dependent methods (syncEmails, sendEmail, etc.) are intentionally
+/// excluded — they are covered by the concrete impl tests.
+abstract class EmailRepositoryContract {
+  static const _account = Account(
+    id: 'er-acc',
+    displayName: 'Contract',
+    email: 'er@example.com',
+    imapHost: 'imap.example.com',
+    smtpHost: 'smtp.example.com',
+  );
+
+  /// Return a fresh [EmailRepository] with [_account] already persisted.
+  Future<EmailRepository> makeRepo();
+
+  /// Insert a raw email row so tests can assert on observable state without
+  /// triggering a network sync.
+  Future<void> insertEmail(
+    EmailRepository repo, {
+    required String id,
+    required String mailboxPath,
+    bool isSeen = true,
+    bool isFlagged = false,
+    DateTime? receivedAt,
+  });
+
+  void run() {
+    test('observeEmails starts empty', () async {
+      final repo = await makeRepo();
+      expect(
+        await repo.observeEmails(_account.id, 'INBOX').first,
+        isEmpty,
+      );
+    });
+
+    test('observeEmails emits inserted email', () async {
+      final repo = await makeRepo();
+      await insertEmail(repo, id: 'er-acc:1', mailboxPath: 'INBOX');
+      final emails = await repo.observeEmails(_account.id, 'INBOX').first;
+      expect(emails, hasLength(1));
+      expect(emails.first.id, 'er-acc:1');
+    });
+
+    test('observeEmails only returns emails for the given mailbox', () async {
+      final repo = await makeRepo();
+      await insertEmail(repo, id: 'er-acc:1', mailboxPath: 'INBOX');
+      expect(
+        await repo.observeEmails(_account.id, 'Sent').first,
+        isEmpty,
+      );
+    });
+
+    test('observeEmails orders by receivedAt descending', () async {
+      final repo = await makeRepo();
+      final older = DateTime(2024);
+      final newer = DateTime(2024, 6);
+      await insertEmail(
+        repo,
+        id: 'er-acc:1',
+        mailboxPath: 'INBOX',
+        receivedAt: older,
+      );
+      await insertEmail(
+        repo,
+        id: 'er-acc:2',
+        mailboxPath: 'INBOX',
+        receivedAt: newer,
+      );
+      final emails = await repo.observeEmails(_account.id, 'INBOX').first;
+      expect(emails.first.id, 'er-acc:2');
+      expect(emails.last.id, 'er-acc:1');
+    });
+
+    test('getEmail returns null for unknown id', () async {
+      final repo = await makeRepo();
+      expect(await repo.getEmail('no-such'), isNull);
+    });
+
+    test('getEmail returns inserted email', () async {
+      final repo = await makeRepo();
+      await insertEmail(repo, id: 'er-acc:7', mailboxPath: 'INBOX');
+      final email = await repo.getEmail('er-acc:7');
+      expect(email, isNotNull);
+      expect(email!.accountId, _account.id);
+    });
+
+    test('setFlag seen updates isSeen', () async {
+      final repo = await makeRepo();
+      await insertEmail(
+        repo,
+        id: 'er-acc:10',
+        mailboxPath: 'INBOX',
+        isSeen: false,
+      );
+      await repo.setFlag('er-acc:10', seen: true);
+      final email = await repo.getEmail('er-acc:10');
+      expect(email!.isSeen, isTrue);
+    });
+
+    test('setFlag flagged updates isFlagged', () async {
+      final repo = await makeRepo();
+      await insertEmail(
+        repo,
+        id: 'er-acc:11',
+        mailboxPath: 'INBOX',
+      );
+      await repo.setFlag('er-acc:11', flagged: true);
+      final email = await repo.getEmail('er-acc:11');
+      expect(email!.isFlagged, isTrue);
+    });
+
+    test('observeThreads starts empty', () async {
+      final repo = await makeRepo();
+      expect(
+        await repo.observeThreads(_account.id, 'INBOX').first,
+        isEmpty,
+      );
+    });
+  }
+}
+
+// ── Impl under test ───────────────────────────────────────────────────────────
+
+class _EmailRepositoryImplContract extends EmailRepositoryContract {
+  static const _account = EmailRepositoryContract._account;
+
+  late AppDatabase _db;
+  late AccountRepositoryImpl _accountRepo;
+
+  @override
+  Future<EmailRepository> makeRepo() async {
+    _db = openTestDatabase();
+    _accountRepo = AccountRepositoryImpl(_db, MapSecureStorage());
+    await _accountRepo.addAccount(_account, 'pw');
+    return EmailRepositoryImpl(
+      _db,
+      _accountRepo,
+      imapConnect: (_, __, ___) => Future<imap.ImapClient>.error(
+        UnsupportedError('no IMAP in unit tests'),
+      ),
+      smtpConnect: (_, __, ___) => Future<imap.SmtpClient>.error(
+        UnsupportedError('no SMTP in unit tests'),
+      ),
+    );
+  }
+
+  @override
+  Future<void> insertEmail(
+    EmailRepository repo, {
+    required String id,
+    required String mailboxPath,
+    bool isSeen = true,
+    bool isFlagged = false,
+    DateTime? receivedAt,
+  }) async {
+    await _db.into(_db.emails).insert(
+          EmailsCompanion.insert(
+            id: id,
+            accountId: _account.id,
+            mailboxPath: mailboxPath,
+            uid: int.parse(id.split(':').last),
+            receivedAt: receivedAt ?? DateTime.now(),
+            isSeen: Value(isSeen),
+            isFlagged: Value(isFlagged),
+          ),
+        );
+  }
+}
+
+void main() {
+  setUpAll(configureSqliteForTests);
+
+  group('EmailRepositoryImpl satisfies EmailRepository contract', () {
+    _EmailRepositoryImplContract().run();
+  });
+}

test/unit/mailbox_repository_contract_test.dart

@@ -0,0 +1,137 @@
+import 'package:drift/drift.dart' show Value;
+import 'package:flutter_test/flutter_test.dart';
+
+import 'package:sharedinbox/core/models/account.dart';
+import 'package:sharedinbox/core/repositories/mailbox_repository.dart';
+import 'package:sharedinbox/data/db/database.dart' hide Account;
+import 'package:sharedinbox/data/repositories/account_repository_impl.dart';
+import 'package:sharedinbox/data/repositories/mailbox_repository_impl.dart';
+
+import 'account_repository_impl_test.dart' show MapSecureStorage;
+import 'db_test_helper.dart';
+
+// ── Contract ──────────────────────────────────────────────────────────────────
+
+/// Verifies the [MailboxRepository] interface contract.
+///
+/// Tests cover only the locally-observable part of the interface
+/// (observe / find) since sync methods require live IMAP/JMAP servers.
+abstract class MailboxRepositoryContract {
+  static const _account = Account(
+    id: 'm-acc',
+    displayName: 'Contract',
+    email: 'm@example.com',
+    imapHost: 'imap.example.com',
+    smtpHost: 'smtp.example.com',
+  );
+
+  /// Return a fresh [MailboxRepository] with [_account] already persisted.
+  Future<MailboxRepository> makeRepo();
+
+  /// Insert a mailbox row into the backing store so tests can verify
+  /// observeMailboxes without triggering a network sync.
+  Future<void> insertMailbox(
+    MailboxRepository repo, {
+    required String id,
+    required String path,
+    String? role,
+    int unread = 0,
+    int total = 0,
+  });
+
+  void run() {
+    test('observeMailboxes starts empty', () async {
+      final repo = await makeRepo();
+      expect(await repo.observeMailboxes(_account.id).first, isEmpty);
+    });
+
+    test('observeMailboxes emits inserted rows ordered by path', () async {
+      final repo = await makeRepo();
+      await insertMailbox(repo, id: 'z', path: 'Z');
+      await insertMailbox(repo, id: 'a', path: 'A');
+      final boxes = await repo.observeMailboxes(_account.id).first;
+      expect(boxes.map((b) => b.path), ['A', 'Z']);
+    });
+
+    test('observeMailboxes only returns rows for the given account', () async {
+      final repo = await makeRepo();
+      await insertMailbox(repo, id: 'mb1', path: 'INBOX');
+      expect(await repo.observeMailboxes('other-acc').first, isEmpty);
+    });
+
+    test('findMailboxByRole returns null when no match', () async {
+      final repo = await makeRepo();
+      expect(
+        await repo.findMailboxByRole(_account.id, 'archive'),
+        isNull,
+      );
+    });
+
+    test('findMailboxByRole returns the matching mailbox', () async {
+      final repo = await makeRepo();
+      await insertMailbox(repo, id: 'arch', path: 'Archive', role: 'archive');
+      final box = await repo.findMailboxByRole(_account.id, 'archive');
+      expect(box, isNotNull);
+      expect(box!.role, 'archive');
+    });
+
+    test('clearForResync removes all mailboxes for the account', () async {
+      final repo = await makeRepo();
+      await insertMailbox(repo, id: 'mb', path: 'INBOX');
+      await repo.clearForResync(_account.id);
+      expect(await repo.observeMailboxes(_account.id).first, isEmpty);
+    });
+  }
+}
+
+// ── Impl under test ───────────────────────────────────────────────────────────
+
+class _MailboxRepositoryImplContract extends MailboxRepositoryContract {
+  static const _account = MailboxRepositoryContract._account;
+
+  late AppDatabase _db;
+  late AccountRepositoryImpl _accountRepo;
+
+  @override
+  Future<MailboxRepository> makeRepo() async {
+    _db = openTestDatabase();
+    _accountRepo = AccountRepositoryImpl(_db, MapSecureStorage());
+    await _accountRepo.addAccount(_account, 'pw');
+    return MailboxRepositoryImpl(
+      _db,
+      _accountRepo,
+      imapConnect: (_, __, ___) =>
+          Future.error(UnsupportedError('no IMAP in unit tests')),
+    );
+  }
+
+  @override
+  Future<void> insertMailbox(
+    MailboxRepository repo, {
+    required String id,
+    required String path,
+    String? role,
+    int unread = 0,
+    int total = 0,
+  }) async {
+    await _db.into(_db.mailboxes).insert(
+          MailboxesCompanion.insert(
+            id: id,
+            accountId: _account.id,
+            path: path,
+            name: path.split('/').last,
+            unreadCount: Value(unread),
+            totalCount: Value(total),
+            role: Value(role),
+          ),
+        );
+  }
+}
+
+void main() {
+  setUpAll(configureSqliteForTests);
+
+  group('MailboxRepositoryImpl satisfies MailboxRepository contract', () {
+    _MailboxRepositoryImplContract().run();
+  });
+}

test/unit/migration_test.dart

@@ -4,11 +4,22 @@ import 'package:flutter_test/flutter_test.dart';
 import 'package:sharedinbox/data/db/database.dart';
 import 'package:sqlite3/sqlite3.dart' as sqlite;
 
+/// Reads all column names for [tableName] from [db].
+Future<List<String>> _tableColumns(AppDatabase db, String tableName) async {
+  final rows = await db.customSelect('PRAGMA table_info($tableName)').get();
+  return rows.map((r) => r.read<String>('name')).toList();
+}
+
 void main() {
   group('Migration', () {
-    test('upgrade from v1 to latest', () async {
+    test('schemaVersion matches expected value', () async {
-      // 1. Create a V1 database using raw sqlite3.
+      final db = AppDatabase(NativeDatabase.memory());
-      final dbFile = File('test_migration.db');
+      expect(db.schemaVersion, 26);
+      await db.close();
+    });
+
+    test('upgrade from v1 to latest checks all added columns', () async {
+      final dbFile = File('test_migration_v1.db');
       if (dbFile.existsSync()) dbFile.deleteSync();
 
       final rawDb = sqlite.sqlite3.open(dbFile.path);
@@ -67,41 +78,265 @@ void main() {
       rawDb.execute('PRAGMA user_version = 1;');
       rawDb.close();
 
-      // 2. Open it with AppDatabase (v22).
       final db = AppDatabase(NativeDatabase(dbFile));
 
-      // Trigger migration by performing a simple query.
+      // Trigger migration by performing a query.
       final accs = await db.select(db.accounts).get();
       expect(accs, hasLength(1));
       expect(accs.first.displayName, 'Alice');
-      expect(accs.first.accountType, 'imap'); // default value
+      expect(accs.first.accountType, 'imap');
 
-      // 3. Verify that all columns exist.
+      // v2–v3: accounts columns.
-      // If migration failed, it would have thrown an exception during opening or query.
+      final accountColumns = await _tableColumns(db, 'accounts');
-      final tableInfo =
+      expect(
-          await db.customSelect('PRAGMA table_info(emails)').get();
+        accountColumns,
-      final columns = tableInfo.map((r) => r.read<String>('name')).toList();
+        containsAll(['account_type', 'jmap_url', 'username']),
-
+      );
-      expect(columns, contains('thread_id'));
-      expect(columns, contains('snoozed_until'));
-      expect(columns, contains('snoozed_from_mailbox_path'));
-
-      final accountsInfo =
-          await db.customSelect('PRAGMA table_info(accounts)').get();
-      final accountColumns =
-          accountsInfo.map((r) => r.read<String>('name')).toList();
-      expect(accountColumns, contains('account_type'));
-      expect(accountColumns, contains('username'));
       expect(accountColumns, contains('manage_sieve_host'));
 
+      // v14: threading columns.
+      final emailColumns = await _tableColumns(db, 'emails');
+      expect(
+        emailColumns,
+        containsAll(['thread_id', 'message_id', 'in_reply_to', 'references']),
+      );
+
+      // v22: snooze columns.
+      expect(
+        emailColumns,
+        containsAll(['snoozed_until', 'snoozed_from_mailbox_path']),
+      );
+
+      // v23: list-unsubscribe header column.
+      expect(emailColumns, contains('list_unsubscribe_header'));
+
+      // v8: mailboxes role column.
+      final mailboxColumns = await _tableColumns(db, 'mailboxes');
+      expect(mailboxColumns, contains('role'));
+
+      // v9: email_bodies cached_at column.
+      final bodyColumns = await _tableColumns(db, 'email_bodies');
+      expect(bodyColumns, contains('cached_at'));
+      expect(bodyColumns, contains('headers_json'));
+
+      // v4: drafts table with v24 imap_server_id column.
+      final draftColumns = await _tableColumns(db, 'drafts');
+      expect(draftColumns, contains('imap_server_id'));
+
+      // v5, v6, v7, v12, v17, v19, v21: new tables.
+      final allTables = await db
+          .customSelect("SELECT name FROM sqlite_master WHERE type='table'")
+          .get();
+      final tableNames = allTables.map((r) => r.read<String>('name')).toList();
+      expect(
+        tableNames,
+        containsAll([
+          'sync_states', // v5
+          'pending_changes', // v6
+          'sync_logs', // v7
+          'sync_log_mailboxes', // v12
+          'threads', // v17
+          'sync_health', // v19
+          'undo_actions', // v21
+        ]),
+      );
+
+      // v18, v22, v25: indexes.
+      final allIndexes = await db
+          .customSelect("SELECT name FROM sqlite_master WHERE type='index'")
+          .get();
+      final indexNames = allIndexes.map((r) => r.read<String>('name')).toSet();
+      expect(
+        indexNames,
+        containsAll([
+          'emails_received_at', // v18
+          'emails_thread_id', // v18
+          'pending_changes_account_id', // v18
+          'emails_snoozed_until', // v22
+          'mailboxes_account_id', // v25
+          'threads_latest_date', // v25
+        ]),
+      );
+
+      // v26: FTS5 virtual table and triggers exist.
+      final allTriggers = await db
+          .customSelect("SELECT name FROM sqlite_master WHERE type='trigger'")
+          .get();
+      final triggerNames =
+          allTriggers.map((r) => r.read<String>('name')).toSet();
+      expect(
+        triggerNames,
+        containsAll(['email_fts_ai', 'email_fts_au', 'email_fts_ad']),
+      );
+      // Verify FTS table was created and is queryable.
+      await db.customSelect('SELECT count(*) FROM email_fts').get();
+
       await db.close();
       if (dbFile.existsSync()) dbFile.deleteSync();
     });
 
-    test('fresh install (v22) works', () async {
+    test(
-      final db = AppDatabase(NativeDatabase.memory());
+        'upgrade from v22 to latest adds list_unsubscribe_header and imap_server_id',
-      // Just ensure we can create everything and query.
+        () async {
+      final dbFile = File('test_migration_v22.db');
+      if (dbFile.existsSync()) dbFile.deleteSync();
+
+      // Build a v22 database schema directly with raw SQL.
+      final rawDb = sqlite.sqlite3.open(dbFile.path);
+      rawDb.execute('''
+        CREATE TABLE accounts (
+          id TEXT NOT NULL PRIMARY KEY,
+          display_name TEXT NOT NULL,
+          email TEXT NOT NULL,
+          imap_host TEXT NOT NULL,
+          imap_port INTEGER NOT NULL DEFAULT 993,
+          imap_ssl INTEGER NOT NULL DEFAULT 1 CHECK ("imap_ssl" IN (0, 1)),
+          smtp_host TEXT NOT NULL DEFAULT '',
+          smtp_port INTEGER NOT NULL DEFAULT 465,
+          smtp_ssl INTEGER NOT NULL DEFAULT 1 CHECK ("smtp_ssl" IN (0, 1)),
+          account_type TEXT NOT NULL DEFAULT 'imap',
+          jmap_url TEXT NULL,
+          username TEXT NULL,
+          manage_sieve_host TEXT NULL,
+          manage_sieve_port INTEGER NULL,
+          manage_sieve_ssl INTEGER NULL,
+          manage_sieve_available INTEGER NOT NULL DEFAULT 0 CHECK ("manage_sieve_available" IN (0, 1)),
+          verbose INTEGER NOT NULL DEFAULT 0 CHECK ("verbose" IN (0, 1))
+        );
+      ''');
+      rawDb.execute('''
+        CREATE TABLE drafts (
+          id INTEGER NOT NULL PRIMARY KEY AUTOINCREMENT,
+          account_id TEXT NULL,
+          reply_to_email_id TEXT NULL,
+          to_text TEXT NOT NULL DEFAULT '',
+          cc_text TEXT NOT NULL DEFAULT '',
+          subject_text TEXT NOT NULL DEFAULT '',
+          body_text TEXT NOT NULL DEFAULT '',
+          updated_at INTEGER NOT NULL
+        );
+      ''');
+      rawDb.execute('''
+        CREATE TABLE mailboxes (
+          id TEXT NOT NULL PRIMARY KEY,
+          account_id TEXT NOT NULL,
+          path TEXT NOT NULL,
+          name TEXT NOT NULL,
+          unread_count INTEGER NOT NULL DEFAULT 0,
+          total_count INTEGER NOT NULL DEFAULT 0,
+          role TEXT NULL
+        );
+      ''');
+      rawDb.execute('''
+        CREATE TABLE emails (
+          id TEXT NOT NULL PRIMARY KEY,
+          account_id TEXT NOT NULL,
+          mailbox_path TEXT NOT NULL,
+          uid INTEGER NOT NULL,
+          subject TEXT NULL,
+          sent_at INTEGER NULL,
+          received_at INTEGER NOT NULL,
+          from_json TEXT NOT NULL DEFAULT '[]',
+          to_addresses TEXT NOT NULL DEFAULT '[]',
+          cc_json TEXT NOT NULL DEFAULT '[]',
+          preview TEXT NULL,
+          is_seen INTEGER NOT NULL DEFAULT 0 CHECK ("is_seen" IN (0, 1)),
+          is_flagged INTEGER NOT NULL DEFAULT 0 CHECK ("is_flagged" IN (0, 1)),
+          has_attachment INTEGER NOT NULL DEFAULT 0 CHECK ("has_attachment" IN (0, 1)),
+          thread_id TEXT NULL,
+          message_id TEXT NULL,
+          in_reply_to TEXT NULL,
+          "references" TEXT NULL,
+          snoozed_until INTEGER NULL,
+          snoozed_from_mailbox_path TEXT NULL
+        );
+      ''');
+      rawDb.execute('''
+        CREATE TABLE threads (
+          account_id TEXT NOT NULL,
+          mailbox_path TEXT NOT NULL,
+          id TEXT NOT NULL,
+          subject TEXT NULL,
+          latest_date INTEGER NOT NULL,
+          message_count INTEGER NOT NULL DEFAULT 1,
+          has_unread INTEGER NOT NULL DEFAULT 0 CHECK ("has_unread" IN (0, 1)),
+          is_flagged INTEGER NOT NULL DEFAULT 0 CHECK ("is_flagged" IN (0, 1)),
+          participants_json TEXT NOT NULL DEFAULT '[]',
+          preview TEXT NULL,
+          latest_email_id TEXT NOT NULL,
+          email_ids_json TEXT NOT NULL DEFAULT '[]',
+          PRIMARY KEY (account_id, mailbox_path, id)
+        );
+      ''');
+      rawDb.execute('PRAGMA user_version = 22;');
+      rawDb.close();
+
+      final db = AppDatabase(NativeDatabase(dbFile));
+      // Trigger migration.
       await db.select(db.accounts).get();
+
+      final emailColumns = await _tableColumns(db, 'emails');
+      expect(emailColumns, contains('list_unsubscribe_header'));
+
+      final draftColumns = await _tableColumns(db, 'drafts');
+      expect(draftColumns, contains('imap_server_id'));
+
+      // v25: new indexes on mailboxes and threads.
+      final allIndexes = await db
+          .customSelect("SELECT name FROM sqlite_master WHERE type='index'")
+          .get();
+      final indexNames = allIndexes.map((r) => r.read<String>('name')).toSet();
+      expect(indexNames, contains('mailboxes_account_id'));
+      expect(indexNames, contains('threads_latest_date'));
+
+      // v26: FTS5 virtual table and triggers.
+      final allTriggers = await db
+          .customSelect("SELECT name FROM sqlite_master WHERE type='trigger'")
+          .get();
+      final triggerNames =
+          allTriggers.map((r) => r.read<String>('name')).toSet();
+      expect(
+        triggerNames,
+        containsAll(['email_fts_ai', 'email_fts_au', 'email_fts_ad']),
+      );
+      await db.customSelect('SELECT count(*) FROM email_fts').get();
+
+      await db.close();
+      if (dbFile.existsSync()) dbFile.deleteSync();
+    });
+
+    test('fresh install creates all tables at schemaVersion 26', () async {
+      final db = AppDatabase(NativeDatabase.memory());
+      await db.select(db.accounts).get();
+
+      final allTables = await db
+          .customSelect("SELECT name FROM sqlite_master WHERE type='table'")
+          .get();
+      final tableNames = allTables.map((r) => r.read<String>('name')).toSet();
+      expect(
+        tableNames,
+        containsAll([
+          'accounts',
+          'mailboxes',
+          'emails',
+          'email_bodies',
+          'drafts',
+          'sync_states',
+          'pending_changes',
+          'sync_logs',
+          'sync_log_mailboxes',
+          'threads',
+          'sync_health',
+          'undo_actions',
+        ]),
+      );
+
+      final emailColumns = await _tableColumns(db, 'emails');
+      expect(emailColumns, contains('list_unsubscribe_header'));
+
+      final draftColumns = await _tableColumns(db, 'drafts');
+      expect(draftColumns, contains('imap_server_id'));
+
       await db.close();
     });
   });

test/unit/reliability_runner_test.dart

@@ -79,9 +79,18 @@ class _CountingEmails implements EmailRepository {
   @override
   Future<int> flushPendingChanges(String accountId, String password) async => 0;
   @override
-  Stream<List<Email>> observeEmails(String a, String m) => Stream.value([]);
+  Stream<List<Email>> observeEmails(
+    String a,
+    String m, {
+    int limit = 50,
+  }) =>
+      Stream.value([]);
   @override
-  Stream<List<EmailThread>> observeThreads(String a, String m) =>
+  Stream<List<EmailThread>> observeThreads(
+    String a,
+    String m, {
+    int limit = 50,
+  }) =>
       Stream.value([]);
   @override
   Stream<List<Email>> observeEmailsInThread(String a, String m, String t) =>

test/unit/undo_service_test.mocks.dart

@@ -75,9 +75,10 @@ class MockEmailRepository extends _i1.Mock implements _i3.EmailRepository {
 
   @override
   _i4.Stream<List<_i2.Email>> observeEmails(
-    String? accountId,
+    String accountId,
-    String? mailboxPath,
+    String mailboxPath, {
-  ) =>
+    int limit = 50,
+  }) =>
       (super.noSuchMethod(
         Invocation.method(
           #observeEmails,
@@ -85,15 +86,17 @@ class MockEmailRepository extends _i1.Mock implements _i3.EmailRepository {
             accountId,
             mailboxPath,
           ],
+          {#limit: limit},
         ),
         returnValue: _i4.Stream<List<_i2.Email>>.empty(),
       ) as _i4.Stream<List<_i2.Email>>);
 
   @override
   _i4.Stream<List<_i2.EmailThread>> observeThreads(
-    String? accountId,
+    String accountId,
-    String? mailboxPath,
+    String mailboxPath, {
-  ) =>
+    int limit = 50,
+  }) =>
       (super.noSuchMethod(
         Invocation.method(
           #observeThreads,
@@ -101,6 +104,7 @@ class MockEmailRepository extends _i1.Mock implements _i3.EmailRepository {
             accountId,
             mailboxPath,
           ],
+          {#limit: limit},
         ),
         returnValue: _i4.Stream<List<_i2.EmailThread>>.empty(),
       ) as _i4.Stream<List<_i2.EmailThread>>);

test/widget/helpers.dart

@@ -30,6 +30,7 @@ import 'package:sharedinbox/ui/screens/email_detail_screen.dart';
 import 'package:sharedinbox/ui/screens/email_list_screen.dart';
 import 'package:sharedinbox/ui/screens/mailbox_list_screen.dart';
 import 'package:sharedinbox/ui/screens/search_screen.dart';
+import 'package:sharedinbox/ui/screens/thread_detail_screen.dart';
 
 // ---------------------------------------------------------------------------
 // Fake repositories
@@ -157,14 +158,19 @@ class FakeEmailRepository implements EmailRepository {
         _emailBody = emailBody ?? const EmailBody(emailId: '', attachments: []);
 
   @override
-  Stream<List<Email>> observeEmails(String accountId, String mailboxPath) =>
+  Stream<List<Email>> observeEmails(
+    String accountId,
+    String mailboxPath, {
+    int limit = 50,
+  }) =>
       Stream.value(List.of(_emails));
 
   @override
   Stream<List<EmailThread>> observeThreads(
     String accountId,
-    String mailboxPath,
+    String mailboxPath, {
-  ) =>
+    int limit = 50,
+  }) =>
       observeEmails(accountId, mailboxPath).map((emails) {
         return emails.map((e) {
           return EmailThread(
@@ -381,6 +387,18 @@ Widget buildApp({
                   ),
                 ],
               ),
+              GoRoute(
+                path: ':mailboxPath/threads/:threadId',
+                builder: (ctx, state) => ThreadDetailScreen(
+                  accountId: state.pathParameters['accountId']!,
+                  mailboxPath: Uri.decodeComponent(
+                    state.pathParameters['mailboxPath']!,
+                  ),
+                  threadId: Uri.decodeComponent(
+                    state.pathParameters['threadId']!,
+                  ),
+                ),
+              ),
             ],
           ),
         ],

test/widget/search_screen_test.dart

@@ -0,0 +1,182 @@
+import 'package:flutter/material.dart';
+import 'package:flutter_test/flutter_test.dart';
+
+import 'package:sharedinbox/core/models/mailbox.dart';
+import 'package:sharedinbox/di.dart';
+
+import 'helpers.dart';
+
+void main() {
+  group('SearchScreen', () {
+    testWidgets('shows placeholder hint text when empty', (tester) async {
+      await tester.pumpWidget(
+        buildApp(
+          initialLocation: '/accounts/acc-1/search',
+          overrides: [
+            accountRepositoryProvider.overrideWithValue(
+              FakeAccountRepository([kTestAccount]),
+            ),
+            mailboxRepositoryProvider.overrideWithValue(
+              FakeMailboxRepository(),
+            ),
+            emailRepositoryProvider.overrideWithValue(FakeEmailRepository()),
+          ],
+        ),
+      );
+      await tester.pumpAndSettle();
+
+      expect(find.text('Type 3+ characters to search'), findsOneWidget);
+    });
+
+    testWidgets('typing fewer than 3 characters does not trigger search', (
+      tester,
+    ) async {
+      await tester.pumpWidget(
+        buildApp(
+          initialLocation: '/accounts/acc-1/search',
+          overrides: [
+            accountRepositoryProvider.overrideWithValue(
+              FakeAccountRepository([kTestAccount]),
+            ),
+            mailboxRepositoryProvider.overrideWithValue(
+              FakeMailboxRepository(),
+            ),
+            emailRepositoryProvider.overrideWithValue(FakeEmailRepository()),
+          ],
+        ),
+      );
+      await tester.pumpAndSettle();
+
+      await tester.enterText(find.byType(TextField), 'hi');
+      await tester.pump(const Duration(milliseconds: 400));
+
+      expect(find.text('Type 3+ characters to search'), findsOneWidget);
+      expect(find.text('No results'), findsNothing);
+    });
+
+    testWidgets('shows "No results" when search returns nothing', (
+      tester,
+    ) async {
+      await tester.pumpWidget(
+        buildApp(
+          initialLocation: '/accounts/acc-1/search',
+          overrides: [
+            accountRepositoryProvider.overrideWithValue(
+              FakeAccountRepository([kTestAccount]),
+            ),
+            mailboxRepositoryProvider.overrideWithValue(
+              FakeMailboxRepository(),
+            ),
+            emailRepositoryProvider.overrideWithValue(FakeEmailRepository()),
+          ],
+        ),
+      );
+      await tester.pumpAndSettle();
+
+      await tester.enterText(find.byType(TextField), 'xyz');
+      await tester.pump(const Duration(milliseconds: 400));
+      await tester.pumpAndSettle();
+
+      expect(find.text('No results'), findsOneWidget);
+    });
+
+    testWidgets('shows email results under "Messages" section', (
+      tester,
+    ) async {
+      final email = testEmail(subject: 'Invoice Q3');
+      await tester.pumpWidget(
+        buildApp(
+          initialLocation: '/accounts/acc-1/search',
+          overrides: [
+            accountRepositoryProvider.overrideWithValue(
+              FakeAccountRepository([kTestAccount]),
+            ),
+            mailboxRepositoryProvider.overrideWithValue(
+              FakeMailboxRepository(),
+            ),
+            emailRepositoryProvider.overrideWithValue(
+              FakeEmailRepository(searchResults: [email]),
+            ),
+          ],
+        ),
+      );
+      await tester.pumpAndSettle();
+
+      await tester.enterText(find.byType(TextField), 'inv');
+      await tester.pump(const Duration(milliseconds: 400));
+      await tester.pumpAndSettle();
+
+      expect(find.text('Messages'), findsOneWidget);
+      expect(find.text('Invoice Q3'), findsOneWidget);
+    });
+
+    testWidgets('shows folder results under "Folders" section', (
+      tester,
+    ) async {
+      const archiveMailbox = Mailbox(
+        id: 'acc-1:Archive',
+        accountId: 'acc-1',
+        path: 'Archive',
+        name: 'Archive',
+        unreadCount: 0,
+        totalCount: 5,
+      );
+      await tester.pumpWidget(
+        buildApp(
+          initialLocation: '/accounts/acc-1/search',
+          overrides: [
+            accountRepositoryProvider.overrideWithValue(
+              FakeAccountRepository([kTestAccount]),
+            ),
+            mailboxRepositoryProvider.overrideWithValue(
+              FakeMailboxRepository([archiveMailbox]),
+            ),
+            emailRepositoryProvider.overrideWithValue(FakeEmailRepository()),
+          ],
+        ),
+      );
+      await tester.pumpAndSettle();
+
+      await tester.enterText(find.byType(TextField), 'arc');
+      await tester.pump(const Duration(milliseconds: 400));
+      await tester.pumpAndSettle();
+
+      expect(find.text('Folders'), findsOneWidget);
+      expect(find.text('Archive'), findsOneWidget);
+    });
+
+    testWidgets('tapping clear button resets results to placeholder', (
+      tester,
+    ) async {
+      final email = testEmail(subject: 'Found email');
+      await tester.pumpWidget(
+        buildApp(
+          initialLocation: '/accounts/acc-1/search',
+          overrides: [
+            accountRepositoryProvider.overrideWithValue(
+              FakeAccountRepository([kTestAccount]),
+            ),
+            mailboxRepositoryProvider.overrideWithValue(
+              FakeMailboxRepository(),
+            ),
+            emailRepositoryProvider.overrideWithValue(
+              FakeEmailRepository(searchResults: [email]),
+            ),
+          ],
+        ),
+      );
+      await tester.pumpAndSettle();
+
+      await tester.enterText(find.byType(TextField), 'found');
+      await tester.pump(const Duration(milliseconds: 400));
+      await tester.pumpAndSettle();
+      expect(find.text('Found email'), findsOneWidget);
+
+      await tester.tap(find.byIcon(Icons.clear));
+      await tester.pumpAndSettle();
+
+      expect(find.text('Found email'), findsNothing);
+      expect(find.text('Type 3+ characters to search'), findsOneWidget);
+    });
+  });
+}

test/widget/thread_detail_screen_test.dart

@@ -0,0 +1,198 @@
+import 'package:flutter/material.dart';
+import 'package:flutter_test/flutter_test.dart';
+
+import 'package:sharedinbox/core/models/email.dart';
+import 'package:sharedinbox/di.dart';
+
+import 'helpers.dart';
+
+Email _threadEmail({
+  String id = 'acc-1:10',
+  bool isFlagged = false,
+  bool isSeen = true,
+}) =>
+    Email(
+      id: id,
+      accountId: 'acc-1',
+      mailboxPath: 'INBOX',
+      uid: 10,
+      threadId: 'thread-1',
+      subject: 'Project update',
+      receivedAt: DateTime(2024, 6),
+      sentAt: DateTime(2024, 6, 1, 9),
+      from: const [EmailAddress(name: 'Bob', email: 'bob@example.com')],
+      to: const [EmailAddress(email: 'alice@example.com')],
+      cc: const [],
+      isSeen: isSeen,
+      isFlagged: isFlagged,
+      hasAttachment: false,
+    );
+
+void main() {
+  group('ThreadDetailScreen', () {
+    testWidgets('shows "Thread not found or empty" when thread is empty', (
+      tester,
+    ) async {
+      await tester.pumpWidget(
+        buildApp(
+          initialLocation: '/accounts/acc-1/mailboxes/INBOX/threads/thread-1',
+          overrides: [
+            accountRepositoryProvider.overrideWithValue(
+              FakeAccountRepository([kTestAccount]),
+            ),
+            mailboxRepositoryProvider.overrideWithValue(
+              FakeMailboxRepository(),
+            ),
+            emailRepositoryProvider.overrideWithValue(FakeEmailRepository()),
+          ],
+        ),
+      );
+      await tester.pumpAndSettle();
+
+      expect(find.text('Thread not found or empty'), findsOneWidget);
+    });
+
+    testWidgets('shows sender name for email in thread', (tester) async {
+      final email = _threadEmail();
+      await tester.pumpWidget(
+        buildApp(
+          initialLocation: '/accounts/acc-1/mailboxes/INBOX/threads/thread-1',
+          overrides: [
+            accountRepositoryProvider.overrideWithValue(
+              FakeAccountRepository([kTestAccount]),
+            ),
+            mailboxRepositoryProvider.overrideWithValue(
+              FakeMailboxRepository(),
+            ),
+            emailRepositoryProvider.overrideWithValue(
+              FakeEmailRepository(emails: [email]),
+            ),
+          ],
+        ),
+      );
+      await tester.pumpAndSettle();
+
+      expect(find.textContaining('Bob'), findsOneWidget);
+    });
+
+    testWidgets('last email in thread is expanded by default', (tester) async {
+      final email = _threadEmail();
+      await tester.pumpWidget(
+        buildApp(
+          initialLocation: '/accounts/acc-1/mailboxes/INBOX/threads/thread-1',
+          overrides: [
+            accountRepositoryProvider.overrideWithValue(
+              FakeAccountRepository([kTestAccount]),
+            ),
+            mailboxRepositoryProvider.overrideWithValue(
+              FakeMailboxRepository(),
+            ),
+            emailRepositoryProvider.overrideWithValue(
+              FakeEmailRepository(
+                emails: [email],
+                emailBody: const EmailBody(
+                  emailId: 'acc-1:10',
+                  textBody: 'Hello body text',
+                  attachments: [],
+                ),
+              ),
+            ),
+          ],
+        ),
+      );
+      await tester.pumpAndSettle();
+
+      // Reply and delete buttons are visible for the expanded card.
+      expect(find.byIcon(Icons.reply), findsOneWidget);
+      expect(find.byIcon(Icons.delete_outline), findsOneWidget);
+    });
+
+    testWidgets('tapping an expanded card collapses it', (tester) async {
+      final email = _threadEmail();
+      await tester.pumpWidget(
+        buildApp(
+          initialLocation: '/accounts/acc-1/mailboxes/INBOX/threads/thread-1',
+          overrides: [
+            accountRepositoryProvider.overrideWithValue(
+              FakeAccountRepository([kTestAccount]),
+            ),
+            mailboxRepositoryProvider.overrideWithValue(
+              FakeMailboxRepository(),
+            ),
+            emailRepositoryProvider.overrideWithValue(
+              FakeEmailRepository(
+                emails: [email],
+                emailBody: const EmailBody(
+                  emailId: 'acc-1:10',
+                  textBody: 'Hello body text',
+                  attachments: [],
+                ),
+              ),
+            ),
+          ],
+        ),
+      );
+      await tester.pumpAndSettle();
+
+      // Tap the expand_less icon to collapse.
+      await tester.tap(find.byIcon(Icons.expand_less));
+      await tester.pumpAndSettle();
+
+      expect(find.byIcon(Icons.reply), findsNothing);
+      expect(find.byIcon(Icons.expand_more), findsOneWidget);
+    });
+
+    testWidgets('flagged email shows star icon', (tester) async {
+      final email = _threadEmail(isFlagged: true);
+      await tester.pumpWidget(
+        buildApp(
+          initialLocation: '/accounts/acc-1/mailboxes/INBOX/threads/thread-1',
+          overrides: [
+            accountRepositoryProvider.overrideWithValue(
+              FakeAccountRepository([kTestAccount]),
+            ),
+            mailboxRepositoryProvider.overrideWithValue(
+              FakeMailboxRepository(),
+            ),
+            emailRepositoryProvider.overrideWithValue(
+              FakeEmailRepository(emails: [email]),
+            ),
+          ],
+        ),
+      );
+      await tester.pumpAndSettle();
+
+      expect(find.byIcon(Icons.star), findsOneWidget);
+    });
+
+    testWidgets('expanded card shows plain text body', (tester) async {
+      final email = _threadEmail();
+      await tester.pumpWidget(
+        buildApp(
+          initialLocation: '/accounts/acc-1/mailboxes/INBOX/threads/thread-1',
+          overrides: [
+            accountRepositoryProvider.overrideWithValue(
+              FakeAccountRepository([kTestAccount]),
+            ),
+            mailboxRepositoryProvider.overrideWithValue(
+              FakeMailboxRepository(),
+            ),
+            emailRepositoryProvider.overrideWithValue(
+              FakeEmailRepository(
+                emails: [email],
+                emailBody: const EmailBody(
+                  emailId: 'acc-1:10',
+                  textBody: 'Body content here',
+                  attachments: [],
+                ),
+              ),
+            ),
+          ],
+        ),
+      );
+      await tester.pumpAndSettle();
+
+      expect(find.text('Body content here'), findsOneWidget);
+    });
+  });
+}