fix(ci): resolve lint errors and test failures

- Fix errcheck: handle watcher.Close() and Set() return values
- Fix unparam: remove always-nil error from NewActivityWatcher
- Fix unparam: remove unused sinceTime param, delete dead code
- Fix version mismatch: update MCP __init__.py to 0.48.0
- Fix routing tests: change CWD so routing can find town root

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

cmd/bd/children.go

@@ -23,8 +23,8 @@ Examples:
 		parentID := args[0]
 
 		// Set the parent flag on listCmd, run it, then reset
-		listCmd.Flags().Set("parent", parentID)
-		defer listCmd.Flags().Set("parent", "")
+		_ = listCmd.Flags().Set("parent", parentID)
+		defer func() { _ = listCmd.Flags().Set("parent", "") }()
 		listCmd.Run(listCmd, []string{})
 	},
 }