fix(sqlite): respect --lock-timeout flag in direct mode (bd-2zd.4)

The ensureStoreActive() function was ignoring the user-configured
--lock-timeout flag and always using the 30s default via sqlite.New().

This fix changes ensureStoreActive() to use sqlite.NewWithTimeout()
with the configured lockTimeout, allowing users to specify shorter
timeouts for multi-agent scenarios.

With this change, users can now run:
  bd --lock-timeout=500ms sync

to fail fast if the database is locked, rather than waiting 30s.

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

cmd/bd/direct_mode.go

@@ -81,8 +81,9 @@ func ensureStoreActive() error {
 	}
 
 	// Use factory to create the appropriate backend (SQLite, Dolt embedded, or Dolt server)
-	// based on metadata.json configuration
-	store, err := factory.NewFromConfig(getRootContext(), beadsDir)
+	// based on metadata.json configuration, with lock timeout support for multi-agent operations
+	opts := factory.Options{LockTimeout: lockTimeout}
+	store, err := factory.NewFromConfigWithOptions(getRootContext(), beadsDir, opts)
 	if err != nil {
 		// Check for fresh clone scenario (JSONL exists but no database)
 		if _, statErr := os.Stat(jsonlPath); statErr == nil {