feat(ci): capture crash evidence as artifacts when a run wedges (T-436)

Closes the observability loop: the log + breadcrumb + watchdog files are now
collected by CI so a wedged run leaves downloadable evidence instead of
nothing.

- logDirectory(): CLIDE_LOG_DIR overrides the per-platform default, so CI can
  point the logs at an uploadable workspace dir (and tests at a temp dir).
  Now takes an injectable env map; tested.
- test_app.dart: when CLIDE_LOG_DIR is set, the testmode harness tees its
  logger to a FileLogSink + spawns the watchdog (off by default — normal
  run-testmode keeps the stderr-only path, no isolate). _say breadcrumbs each
  test into the file.
- conpty_orphan_probe.dart: with CLIDE_LOG_DIR set it passes a verbose PtyLog,
  so when soak-conpty-kill.ps1 force-kills the parent, the reader/waiter
  isolates' LAST crumb is fsynced to disk — naming what the wedged isolate was
  doing at the instant of death.
- bundle-smoke job: runs the real release app with CLIDE_LOG=debug +
  CLIDE_LOG_DIR, uploads clide-logs (watchdog heartbeat/sample + FileLogSink)
  in an always() step.
- windows-soak kill-probe job: sets CLIDE_LOG_DIR, uploads the FFI crumbs.

Coverage gate 95.08%.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

lib/src/ipc/paths.dart

@@ -65,18 +65,26 @@ String socketDirectory() {
 /// on logout/reboot — this is a DURABLE location. The whole point of the
 /// FileLogSink is that a freeze's last breadcrumbs survive the power-cycle, so
 /// the log dir must outlive a reboot.
-String logDirectory() {
+///
+/// `CLIDE_LOG_DIR` overrides everything: CI points it at a workspace dir
+/// outside the build tree so a wedged run's logs can be uploaded as an
+/// artifact (T-436), and tests redirect it to a temp dir.
+/// [env] defaults to [Platform.environment]; injectable for tests.
+String logDirectory([Map<String, String>? env]) {
+  final e = env ?? Platform.environment;
+  final override = e['CLIDE_LOG_DIR'];
+  if (override != null && override.isNotEmpty) return override;
   if (Platform.isWindows) {
-    final local = Platform.environment['LOCALAPPDATA'];
-    final base = (local != null && local.isNotEmpty) ? local : '${Platform.environment['USERPROFILE'] ?? r'C:\'}\\AppData\\Local';
+    final local = e['LOCALAPPDATA'];
+    final base = (local != null && local.isNotEmpty) ? local : '${e['USERPROFILE'] ?? r'C:\'}\\AppData\\Local';
     return '$base\\clide\\logs';
   }
   if (Platform.isMacOS) {
-    final home = Platform.environment['HOME'] ?? '/tmp';
+    final home = e['HOME'] ?? '/tmp';
     return '$home/Library/Logs/clide';
   }
-  final state = Platform.environment['XDG_STATE_HOME'];
-  final base = (state != null && state.isNotEmpty) ? state : '${Platform.environment['HOME'] ?? '/tmp'}/.local/state';
+  final state = e['XDG_STATE_HOME'];
+  final base = (state != null && state.isNotEmpty) ? state : '${e['HOME'] ?? '/tmp'}/.local/state';
   return '$base/clide/logs';
 }
 

lib/test_app.dart

@@ -31,6 +31,7 @@ import 'kernel/kernel.dart';
 import 'src/pty/ffi/libc.dart' as libc;
 import 'src/daemon/pane_commands.dart';
 import 'src/ipc/envelope.dart';
+import 'src/ipc/paths.dart' show logDirectory;
 import 'src/panes/event_sink.dart';
 import 'src/panes/registry.dart';
 import 'src/daemon/dispatcher.dart';
@@ -59,6 +60,7 @@ class _ClideTestAppState extends State<ClideTestApp> {
   @override
   void initState() {
     super.initState();
+    _attachCrashLogging();
     WidgetsBinding.instance.addPostFrameCallback((_) => _runTests());
     Timer(_timeout, () {
       _say('timeout reached — exiting');
@@ -66,6 +68,28 @@ class _ClideTestAppState extends State<ClideTestApp> {
     });
   }
 
+  /// Opt-in crash evidence for testmode (T-436): when `CLIDE_LOG_DIR` is set
+  /// (CI / a manual Windows repro), tee this harness's logger to a
+  /// FileLogSink and spawn the watchdog, so a wedged testmode run leaves the
+  /// same log + watchdog files the real app would. `_say` breadcrumbs each
+  /// test through the logger, so they land in the file too. Off by default —
+  /// normal `make run-testmode` keeps the stderr-only path, no isolate.
+  void _attachCrashLogging() {
+    final dir = Platform.environment['CLIDE_LOG_DIR'];
+    if (dir == null || dir.isEmpty) return;
+    final logDir = logDirectory();
+    try {
+      _logger.addSink(FileLogSink(dir: Directory(logDir)).call);
+    } catch (_) {}
+    unawaited(_spawnWatchdog(logDir));
+  }
+
+  Future<void> _spawnWatchdog(String logDir) async {
+    try {
+      await Isolate.spawn(watchdogEntry, ('$logDir/clide-watchdog.log', 500, 2000));
+    } catch (_) {}
+  }
+
   Future<void> _runTests() async {
     const workspace = String.fromEnvironment('CLIDE_PROJECT');
     const category = String.fromEnvironment('CLIDE_TESTMODE');