fix(sync): initialize store after daemon disconnect (GH#984)

The sync command was closing the daemon connection without initializing
the direct store, leaving store=nil. This caused errors in post-checkout
hook when running bd sync --import-only.

Fixed by using fallbackToDirectMode() which properly closes daemon and
initializes the store.

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

cmd/bd/sync.go

@@ -65,10 +65,16 @@ Use --merge to merge the sync branch back to main branch.`,
 		// (e.g., during recovery), the daemon's SQLite connection points to the old
 		// (deleted) file, causing export to return incomplete/corrupt data.
 		// Using direct mode ensures we always read from the current database file.
+		//
+		// GH#984: Must use fallbackToDirectMode() instead of just closing daemon.
+		// When connected to daemon, PersistentPreRun skips store initialization.
+		// Just closing daemon leaves store=nil, causing "no database store available"
+		// errors in post-checkout hook's `bd sync --import-only`.
 		if daemonClient != nil {
 			debug.Logf("sync: forcing direct mode for consistency")
-			_ = daemonClient.Close()
-			daemonClient = nil
+			if err := fallbackToDirectMode("sync requires direct database access"); err != nil {
+				FatalError("failed to initialize direct mode: %v", err)
+			}
 		}
 
 		// Initialize local store after daemon disconnect.