feat: split search query into words for AND semantics

Searching for "foo bar" now matches emails containing both words rather
than the exact phrase. Each whitespace-separated term generates its own
IMAP criterion (OR SUBJECT "w" TEXT "w") — multiple top-level IMAP criteria
are ANDed by the protocol — and its own Drift LIKE clause for the local DB.

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

done.md

@@ -6,6 +6,17 @@ Tasks get moved from next.md to done.md
 
 ## Tasks
 
+## Multi-word search uses AND semantics
+
+Searching for "foo bar" now returns emails that contain **both** words, not the exact
+phrase. Fixed in `email_repository_impl.dart`:
+
+- **IMAP search** (`searchEmails`): query is split on whitespace; each word becomes
+  `OR SUBJECT "word" TEXT "word"`, joined by spaces. Multiple top-level IMAP criteria
+  are implicitly ANDed by the protocol.
+- **Local DB search** (`searchEmailsGlobal`): each word adds
+  `& (subject LIKE '%word%' | preview LIKE '%word%')` to the Drift where-clause.
+
 ## Navigate back to account list from inside an account
 
 Added an "All accounts" tile (with `Icons.switch_account`) at the top of `FolderDrawer`,

lib/data/repositories/email_repository_impl.dart

@@ -1726,13 +1726,21 @@ class EmailRepositoryImpl implements EmailRepository {
     String accountId,
     String query,
   ) async {
-    final pattern = '%${query.toLowerCase()}%';
+    final words = query
+        .toLowerCase()
+        .split(RegExp(r'\s+'))
+        .where((w) => w.isNotEmpty)
+        .toList();
     final rows = await (_db.select(_db.emails)
-          ..where(
-            (t) =>
-                t.accountId.equals(accountId) &
-                (t.subject.like(pattern) | t.preview.like(pattern)),
-          )
+          ..where((t) {
+            Expression<bool> condition = t.accountId.equals(accountId);
+            for (final word in words) {
+              final pattern = '%$word%';
+              condition = condition &
+                  (t.subject.like(pattern) | t.preview.like(pattern));
+            }
+            return condition;
+          })
           ..orderBy([(t) => OrderingTerm.desc(t.receivedAt)])
           ..limit(50))
         .get();
@@ -1770,9 +1778,14 @@ class EmailRepositoryImpl implements EmailRepository {
         await _imapConnect(account, _effectiveUsername(account), password);
     try {
       await client.selectMailboxByPath(mailboxPath);
-      final escaped = query.replaceAll('"', '\\"');
+      final terms =
+          query.split(RegExp(r'\s+')).where((t) => t.isNotEmpty).toList();
+      final searchCriteria = terms.map((term) {
+        final escaped = term.replaceAll('"', '\\"');
+        return 'OR SUBJECT "$escaped" TEXT "$escaped"';
+      }).join(' ');
       final result = await client.uidSearchMessages(
-        searchCriteria: 'OR SUBJECT "$escaped" TEXT "$escaped"',
+        searchCriteria: searchCriteria,
       );
       final uids = result.matchingSequence?.toList() ?? [];
       if (uids.isEmpty) return [];

next.md

@@ -18,11 +18,6 @@ Then commit.
 
 ## Tasks
 
-I opened a mailbox. I search for "foo bar". I want to see all mails containing foo and bar. Not
-mails containing "foo bar" exactly.
-
----
-
 I search for "foo". Now I see all mails containing "foo". I want to easily do the common actions on
 the selected mails: Delete, Archive, Move to Folder, Move to Junk, ...