perf: cache Linux engine artifacts via flutter precache --linux (#129)

Add flutter precache --linux --no-android --no-ios to toolchain() so
the Linux engine binaries are baked into the execution-cache snapshot
rather than downloaded on demand during each flutter build linux run.

.forgejo/workflows/monitor.yml

@@ -1,18 +0,0 @@
-name: Monitor Agent Loop
-
-on:
-  schedule:
-    - cron: '0 */2 * * *'  # every 2 hours
-  workflow_dispatch:
-
-jobs:
-  monitor:
-    name: Check Agent Loop Health
-    runs-on: ubuntu-latest
-    timeout-minutes: 5
-
-    steps:
-      - uses: actions/checkout@v4
-
-      - name: Check agent loop heartbeat
-        run: python3 scripts/agent_loop.py monitor

ci/main.go

@@ -195,7 +195,8 @@ func (m *Ci) toolchain() *dagger.Container {
 		WithUser("ci").
 		WithExec([]string{"/bin/sh", "-c",
 			`tmp=$(mktemp); trap 'rm -f "$tmp"' EXIT; ` +
-				`yes | sdkmanager "ndk;28.2.13676358" "cmake;3.22.1" "build-tools;35.0.0" "platforms;android-34" >"$tmp" 2>&1 || { cat "$tmp"; exit 1; }`})
+				`yes | sdkmanager "ndk;28.2.13676358" "cmake;3.22.1" "build-tools;35.0.0" "platforms;android-34" >"$tmp" 2>&1 || { cat "$tmp"; exit 1; }`}).
+		WithExec([]string{"flutter", "precache", "--linux", "--no-android", "--no-ios"})
 }
 
 // Base is the Flutter toolchain container with mutable cache mounts attached.
@@ -810,7 +811,7 @@ func (m *Ci) Graph() string {
 ` + "```" + `mermaid
 flowchart TD
     subgraph dagger ["Dagger · Check pipeline"]
-        toolchain["toolchain\nflutter:3.41.6 + NDK + apt"]
+        toolchain["toolchain\nflutter:3.41.6 + NDK + apt + precache"]
         pubGet["pubGetLayer\nflutter pub get"]
         codegen["codegenBase\nbuild_runner build\n(shared cache)"]
         stalwart(["Stalwart service\nIMAP · JMAP · SMTP · Sieve"])

lib/ui/screens/account_receive_screen.dart

@@ -37,9 +37,6 @@ class _AccountReceiveScreenState extends ConsumerState<AccountReceiveScreen> {
   bool _scannerActive = false;
 
   MobileScannerController? _scannerController;
-  // True when the scanner plugin fails to initialise at runtime (e.g.
-  // MissingPluginException on some Android builds).
-  bool _scannerFailed = false;
 
   @override
   void initState() {
@@ -79,35 +76,8 @@ class _AccountReceiveScreenState extends ConsumerState<AccountReceiveScreen> {
     setState(() {
       _step = _Step.scanning;
       _scannerActive = true;
+      _scannerController = MobileScannerController();
     });
-    if (_cameraScanSupported()) {
-      unawaited(_initScanner());
-    }
-  }
-
-  // Pre-flight: start + stop the scanner to verify the plugin is available.
-  // Falls back to text entry on any exception (including MissingPluginException).
-  Future<void> _initScanner() async {
-    MobileScannerController? ctrl;
-    bool available = false;
-    try {
-      ctrl = MobileScannerController();
-      await ctrl.start();
-      await ctrl.stop();
-      available = true;
-    } catch (_) {
-      // Plugin not available on this device; text fallback will be shown.
-    } finally {
-      try {
-        await ctrl?.dispose();
-      } catch (_) {}
-    }
-    if (!mounted) return;
-    if (available) {
-      setState(() => _scannerController = MobileScannerController());
-    } else {
-      setState(() => _scannerFailed = true);
-    }
   }
 
   Future<void> _onScanned(String rawValue) async {
@@ -296,14 +266,11 @@ class _AccountReceiveScreenState extends ConsumerState<AccountReceiveScreen> {
   }
 
   Widget _buildScannerView(BuildContext context) {
-    // Fall back to text input when the platform has no camera support or when
-    // the scanner plugin fails to initialise at runtime (MissingPluginException).
-    if (!_cameraScanSupported() || _scannerFailed) {
+    // On platforms where the camera scanner is not available (Linux desktop),
+    // fall back to a text-input field.
+    if (!_cameraScanSupported()) {
       return _buildTextFallbackView(context);
     }
-    if (_scannerController == null) {
-      return const Center(child: CircularProgressIndicator());
-    }
 
     return Stack(
       children: [

lib/ui/screens/account_send_screen.dart

@@ -45,40 +45,12 @@ class _AccountSendScreenState extends ConsumerState<AccountSendScreen> {
   bool _scannerActive = true;
 
   MobileScannerController? _scannerController;
-  // True when the scanner plugin fails to initialise at runtime (e.g.
-  // MissingPluginException on some Android builds).
-  bool _scannerFailed = false;
 
   @override
   void initState() {
     super.initState();
     if (_cameraScanSupported()) {
-      unawaited(_initScanner());
-    }
-  }
-
-  // Pre-flight: start + stop the scanner to verify the plugin is available.
-  // Falls back to text entry on any exception (including MissingPluginException).
-  Future<void> _initScanner() async {
-    MobileScannerController? ctrl;
-    bool available = false;
-    try {
-      ctrl = MobileScannerController();
-      await ctrl.start();
-      await ctrl.stop();
-      available = true;
-    } catch (_) {
-      // Plugin not available on this device; text fallback will be shown.
-    } finally {
-      try {
-        await ctrl?.dispose();
-      } catch (_) {}
-    }
-    if (!mounted) return;
-    if (available) {
-      setState(() => _scannerController = MobileScannerController());
-    } else {
-      setState(() => _scannerFailed = true);
+      _scannerController = MobileScannerController();
     }
   }
 
@@ -206,12 +178,9 @@ class _AccountSendScreenState extends ConsumerState<AccountSendScreen> {
   }
 
   Widget _buildScanStep(BuildContext context) {
-    if (!_cameraScanSupported() || _scannerFailed) {
+    if (!_cameraScanSupported()) {
       return _buildTextFallbackView(context);
     }
-    if (_scannerController == null) {
-      return const Center(child: CircularProgressIndicator());
-    }
 
     return Stack(
       children: [

scripts/agent_loop.py

@@ -53,9 +53,7 @@ os.environ["PATH"] = (
 REPO = "guettli/sharedinbox"
 REPO_URL = f"https://codeberg.org/{REPO}"
 STATE_FILE = Path.home() / ".sharedinbox-agent-state.json"
-HEARTBEAT_FILE = Path.home() / ".sharedinbox-agent-heartbeat"
 MAX_AGENT_AGE_SECONDS = 3600  # 1 hour
-MAX_HEARTBEAT_AGE_SECONDS = 7200  # 2 hours
 CLAUDE_PROJECTS_DIR = Path.home() / ".claude" / "projects" / (
     "-" + str(Path.home())[1:].replace("/", "-")
 )
@@ -275,12 +273,6 @@ def _clear_state() -> None:
     STATE_FILE.unlink(missing_ok=True)
 
 
-def _update_heartbeat() -> None:
-    """Record that the agent loop ran right now."""
-    HEARTBEAT_FILE.write_text(datetime.now(timezone.utc).isoformat())
-    HEARTBEAT_FILE.chmod(0o600)
-
-
 def _find_session_uuid(session_name: str) -> str | None:
     """Return the Claude session UUID for *session_name*, or None if not found.
 
@@ -450,44 +442,12 @@ def cmd_list() -> int:
     return 0
 
 
-# ── monitor subcommand ────────────────────────────────────────────────────────
-
-
-def cmd_monitor() -> int:
-    """Check that the agent loop has run within the last 2 hours.
-
-    Exits 0 if healthy, 1 if the heartbeat is missing or stale.
-    Intended to be called from a scheduled CI job or cron every 2 hours.
-    """
-    if not HEARTBEAT_FILE.exists():
-        print(
-            f"WARNING: Agent loop heartbeat file missing — "
-            f"the loop may not have run yet or the file was deleted ({HEARTBEAT_FILE})."
-        )
-        return 1
-    try:
-        last_run = datetime.fromisoformat(HEARTBEAT_FILE.read_text().strip())
-    except ValueError:
-        print(f"WARNING: Agent loop heartbeat file is corrupted: {HEARTBEAT_FILE}")
-        return 1
-    age = (datetime.now(timezone.utc) - last_run).total_seconds()
-    if age > MAX_HEARTBEAT_AGE_SECONDS:
-        print(
-            f"WARNING: Agent loop last ran {age / 3600:.1f}h ago "
-            f"(limit: {MAX_HEARTBEAT_AGE_SECONDS // 3600}h) — the loop may be stalled."
-        )
-        return 1
-    print(f"Agent loop is healthy. Last run: {age / 60:.0f} min ago.")
-    return 0
-
-
 # ── main flow ─────────────────────────────────────────────────────────────────
 
 
 def _run_loop() -> int:
     now = datetime.now(timezone.utc)
     print(f"---------------------- Starting {now.strftime('%Y-%m-%d %H:%MZ')}")
-    _update_heartbeat()
 
     state = _read_state()
 
@@ -835,13 +795,10 @@ def main() -> int:
     parser = argparse.ArgumentParser(prog="agent_loop")
     sub = parser.add_subparsers(dest="cmd")
     sub.add_parser("list", help="List recent agent sessions")
-    sub.add_parser("monitor", help="Check that the loop ran within the last 2 hours")
     args = parser.parse_args()
 
     if args.cmd == "list":
         return cmd_list()
-    if args.cmd == "monitor":
-        return cmd_monitor()
     return _run_loop()
 
 

scripts/test_agent_loop.py

@@ -6,7 +6,6 @@ import json
 import os
 import tempfile
 import unittest
-from datetime import datetime, timedelta, timezone
 from pathlib import Path
 from unittest.mock import MagicMock, patch
 
@@ -733,70 +732,5 @@ class TestRunLoopResumeCommand(unittest.TestCase):
         self.assertNotIn("Resume:", output)
 
 
-class TestHeartbeat(unittest.TestCase):
-    """Tests for _update_heartbeat() and cmd_monitor()."""
-
-    def setUp(self):
-        self._tmp = tempfile.NamedTemporaryFile(delete=False, suffix=".heartbeat")
-        self._tmp.close()
-        self._orig = agent_loop.HEARTBEAT_FILE
-        agent_loop.HEARTBEAT_FILE = Path(self._tmp.name)
-        Path(self._tmp.name).unlink()  # Start with no heartbeat file.
-
-    def tearDown(self):
-        agent_loop.HEARTBEAT_FILE = self._orig
-        Path(self._tmp.name).unlink(missing_ok=True)
-
-    def test_update_heartbeat_writes_timestamp(self):
-        agent_loop._update_heartbeat()
-        content = Path(self._tmp.name).read_text().strip()
-        dt = datetime.fromisoformat(content)
-        age = (datetime.now(timezone.utc) - dt).total_seconds()
-        self.assertLess(age, 5)
-
-    def test_update_heartbeat_creates_file(self):
-        self.assertFalse(Path(self._tmp.name).exists())
-        agent_loop._update_heartbeat()
-        self.assertTrue(Path(self._tmp.name).exists())
-
-    def test_monitor_healthy_when_recent(self):
-        agent_loop._update_heartbeat()
-        result = agent_loop.cmd_monitor()
-        self.assertEqual(result, 0)
-
-    def test_monitor_warns_when_heartbeat_missing(self):
-        buf = io.StringIO()
-        with contextlib.redirect_stdout(buf):
-            result = agent_loop.cmd_monitor()
-        self.assertEqual(result, 1)
-        self.assertIn("WARNING", buf.getvalue())
-
-    def test_monitor_warns_when_stale(self):
-        stale = (datetime.now(timezone.utc) - timedelta(hours=3)).isoformat()
-        Path(self._tmp.name).write_text(stale)
-        buf = io.StringIO()
-        with contextlib.redirect_stdout(buf):
-            result = agent_loop.cmd_monitor()
-        self.assertEqual(result, 1)
-        self.assertIn("WARNING", buf.getvalue())
-
-    def test_monitor_warns_when_corrupted(self):
-        Path(self._tmp.name).write_text("not-a-timestamp")
-        buf = io.StringIO()
-        with contextlib.redirect_stdout(buf):
-            result = agent_loop.cmd_monitor()
-        self.assertEqual(result, 1)
-        self.assertIn("WARNING", buf.getvalue())
-
-    def test_run_loop_updates_heartbeat(self):
-        self.assertFalse(Path(self._tmp.name).exists())
-        with patch("agent_loop._read_state", return_value=None), \
-             patch("agent_loop._open_issue_prs", return_value=[]), \
-             patch("agent_loop._latest_main_ci_run", return_value=None), \
-             patch("agent_loop._ready_issues", return_value=[]):
-            agent_loop._run_loop()
-        self.assertTrue(Path(self._tmp.name).exists())
-
-
 if __name__ == "__main__":
     unittest.main()