share DaemonBus between backend and kernel, fix terminal spawn timing

The IsolateClient and KernelServices now share the same DaemonBus.
Previously, backend events (pane.output, git.changed) went to a
separate bus that widgets couldn't see.

ClaudePane._spawnWhenReady waits for ProjectOpened before sending
pane.spawn, preventing "No project active" errors.

Recents loaded before runApp so the welcome screen shows them.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

lib/kernel/src/facade.dart

@@ -107,9 +107,10 @@ class KernelServices {
     Toolchain? toolchain,
     Future<void> Function(String path)? onProjectOpen,
     Future<String?> Function(String path)? onValidateProject,
+    DaemonBus? sharedBus,
   }) async {
     final log = Logger();
-    final events = DaemonBus();
+    final events = sharedBus ?? DaemonBus();
     final messages = MessageBus();
 
     final settings = SettingsStore(appDir: appDir);