Clean up snapshot files after successful merge (bd-auf1)

Amp-Thread-ID: https://ampcode.com/threads/T-15e8dbc1-4706-4640-883e-6830a8e79fe8
Co-authored-by: Amp <amp@ampcode.com>

cmd/bd/sync.go

@@ -269,6 +269,12 @@ Use --merge to merge the sync branch back to main branch.`,
 				if err := updateBaseSnapshot(jsonlPath); err != nil {
 					fmt.Fprintf(os.Stderr, "Warning: failed to update base snapshot: %v\n", err)
 				}
+
+				// Clean up temporary snapshot files after successful merge
+				sm := NewSnapshotManager(jsonlPath)
+				if err := sm.Cleanup(); err != nil {
+					fmt.Fprintf(os.Stderr, "Warning: failed to clean up snapshots: %v\n", err)
+				}
 			}
 		}