diff --git a/lib/core/sync/account_sync_manager.dart b/lib/core/sync/account_sync_manager.dart
index 75bfa49..91a45ea 100644
--- a/lib/core/sync/account_sync_manager.dart
+++ b/lib/core/sync/account_sync_manager.dart
@@ -1,6 +1,7 @@
 import 'dart:async';
 
 import 'package:enough_mail/enough_mail.dart' as imap;
+import 'package:flutter/services.dart' show MissingPluginException;
 import 'package:sharedinbox/core/models/account.dart';
 import 'package:sharedinbox/core/models/email.dart' show SyncEmailsResult;
 import 'package:sharedinbox/core/repositories/account_repository.dart';
@@ -294,6 +295,7 @@ class _AccountSync implements _SyncLoop {
 
   bool _isPermanentError(Object e) {
     if (isTlsConfigError(e)) return true;
+    if (e is MissingPluginException) 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') ||
@@ -546,6 +548,7 @@ class _JmapAccountSync implements _SyncLoop {
 
   bool _isPermanentError(Object e) {
     if (isTlsConfigError(e)) return true;
+    if (e is MissingPluginException) return true;
     final s = e.toString().toLowerCase();
     return s.contains('invalid credentials') ||
         s.contains('authentication failed') ||
diff --git a/scripts/agent_loop.py b/scripts/agent_loop.py
index c63eaec..26c3845 100755
--- a/scripts/agent_loop.py
+++ b/scripts/agent_loop.py
@@ -31,6 +31,7 @@ To resume the Claude conversation, look up the session UUID first:
 import argparse
 import json
 import os
+import re
 import shlex
 import subprocess
 import sys
@@ -188,6 +189,40 @@ def _find_pr_for_branch(branch: str, state: str = "open") -> dict | None:
     return None
 
 
+def _open_issue_prs() -> list[dict]:
+    """Return all open PRs with issue-{N}-fix branches, oldest-first."""
+    result = subprocess.run(
+        ["fgj", "--hostname", "codeberg.org", "pr", "list",
+         "--repo", REPO, "--state", "open", "--json"],
+        capture_output=True, text=True,
+    )
+    if result.returncode != 0 or not result.stdout.strip():
+        return []
+    prs = json.loads(result.stdout)
+    issue_prs = []
+    for pr in prs:
+        head = pr.get("head", {})
+        ref = head.get("ref") or head.get("label", "").split(":")[-1]
+        if re.match(r"^issue-\d+-fix$", ref or ""):
+            issue_prs.append(pr)
+    issue_prs.sort(key=lambda p: p["number"])
+    return issue_prs
+
+
+def _latest_ci_run_for_pr(pr_number: int) -> dict | None:
+    """Return the latest CI run triggered by a pull_request event for the given PR number."""
+    data = _tea_get(f"repos/{REPO}/actions/runs?event=pull_request&limit=50")
+    runs = (data or {}).get("workflow_runs", [])
+    for run in runs:
+        try:
+            payload = json.loads(run.get("event_payload", "{}"))
+            if payload.get("pull_request", {}).get("number") == pr_number:
+                return run
+        except (json.JSONDecodeError, AttributeError):
+            pass
+    return None
+
+
 def _merge_pr(pr_number: int) -> None:
     """Squash-merge a PR via fgj."""
     _fgj("pr", "merge", str(pr_number), "--repo", REPO, "--merge-method", "squash")
@@ -538,6 +573,38 @@ def _run_loop() -> int:
         )
         return 0
 
+    # ── 2b. Catch-up: scan open issue-N-fix PRs orphaned by a cleared state ─────
+    # This handles PRs whose CI has passed but were never merged because the
+    # state file was cleared (loop restart, killed agent, manual intervention).
+    open_prs = _open_issue_prs()
+    for pr in open_prs:
+        pr_number = pr["number"]
+        pr_url = f"{REPO_URL}/pulls/{pr_number}"
+        head = pr.get("head", {})
+        branch = head.get("ref") or head.get("label", "").split(":")[-1]
+        m = re.match(r"^issue-(\d+)-fix$", branch or "")
+        issue_num = int(m.group(1)) if m else None
+        pr_run = _latest_ci_run_for_pr(pr_number)
+
+        if pr_run and pr_run.get("status") == "running":
+            print(f"Catch-up: CI {_ci_run_url(pr_run['id'])} on PR #{pr_number} still running. Waiting.")
+            _write_state(None, issue_num, "pending-ci")
+            return 0
+
+        if pr_run and pr_run.get("status") in ("failure", "error"):
+            print(f"Catch-up: CI {_ci_run_url(pr_run['id'])} on PR #{pr_number} failed — skipping.")
+            continue
+
+        if pr_run and pr_run.get("status") == "success":
+            print(f"Catch-up: CI passed on PR #{pr_number} ({pr_url}) — merging.")
+            _merge_pr(pr_number)
+            if issue_num:
+                _close_issue(issue_num)
+                print(f"Merged PR #{pr_number} and closed issue #{issue_num}.")
+            else:
+                print(f"Merged PR #{pr_number}.")
+            return 0
+
     # ── 3. Global CI check (agent pushed to main, or no pending issue) ────────
     run = _latest_ci_run()
 
diff --git a/test/unit/account_sync_manager_test.dart b/test/unit/account_sync_manager_test.dart
index 55371a5..d053583 100644
--- a/test/unit/account_sync_manager_test.dart
+++ b/test/unit/account_sync_manager_test.dart
@@ -1,6 +1,8 @@
 import 'dart:async';
 
+import 'package:flutter/services.dart' show MissingPluginException;
 import 'package:mockito/annotations.dart';
+import 'package:sharedinbox/core/models/account.dart';
 import 'package:sharedinbox/core/models/email.dart';
 import 'package:sharedinbox/core/models/mailbox.dart';
 import 'package:sharedinbox/core/repositories/account_repository.dart';
@@ -30,6 +32,40 @@ void main() {
     // This is hard to test without real loops, but we can verify it doesn't crash.
     manager.syncNow('unknown');
   });
+
+  // Regression test for issue #200: when flutter_secure_storage throws
+  // MissingPluginException (channel unavailable on the device), the IMAP sync
+  // loop must stop permanently instead of retrying indefinitely with backoff.
+  test(
+      'MissingPluginException from secure storage stops IMAP sync loop permanently',
+      () async {
+    final syncLog = FakeSyncLogRepository();
+
+    final m = AccountSyncManager(
+      _AccountRepositoryWithMissingPlugin(),
+      FakeMailboxRepositoryWithInbox(),
+      FakeEmailRepository(),
+      syncLog: syncLog,
+    );
+
+    m.start();
+
+    // Allow the first sync cycle to run and fail.
+    await Future<void>.delayed(const Duration(milliseconds: 100));
+
+    expect(syncLog.logs, hasLength(1));
+    expect(syncLog.logs.first.success, isFalse);
+
+    // Kicking the loop should have no effect once it has stopped permanently.
+    m.syncNow('1');
+    await Future<void>.delayed(const Duration(milliseconds: 100));
+
+    // Before the fix: kick triggers a retry → 2 log entries.
+    // After the fix: loop is permanently stopped → still exactly 1 entry.
+    expect(syncLog.logs, hasLength(1));
+
+    m.dispose();
+  });
 }
 
 class FakeEmailRepository implements EmailRepository {
@@ -187,3 +223,34 @@ class FakeMailboxRepositoryWithInbox implements MailboxRepository {
   @override
   Future<void> clearForResync(String accountId) async {}
 }
+
+class _AccountRepositoryWithMissingPlugin implements AccountRepository {
+  static const _account = Account(
+    id: '1',
+    displayName: 'Test',
+    email: 'test@example.com',
+  );
+
+  @override
+  Stream<List<Account>> observeAccounts() => Stream.value([_account]);
+
+  @override
+  Future<Account?> getAccount(String id) async => _account;
+
+  @override
+  Future<String> getPassword(String accountId) => Future.error(
+        MissingPluginException(
+          'No implementation found for method read on channel '
+          'plugins.it.nomads.com/flutter_secure_storage',
+        ),
+      );
+
+  @override
+  Future<void> addAccount(Account account, String password) async {}
+
+  @override
+  Future<void> updateAccount(Account account, {String? password}) async {}
+
+  @override
+  Future<void> removeAccount(String id) async {}
+}