refactor!: remove redundant compatibility layers

Use native browser and Tauri behavior instead of custom selector, dialog, and window-state implementations. Remove obsolete bridge, relay, asset, and dependency paths to keep the supported surface small.

BREAKING CHANGE: The Noctalia relay no longer accepts --agent, and the Tauri host no longer exposes the legacy load_agent command.

ui/src/workspace/useWorkspace.ts

@@ -1,6 +1,5 @@
 import { invoke } from "@tauri-apps/api/core";
 import { listen } from "@tauri-apps/api/event";
-import { getCurrentWindow } from "@tauri-apps/api/window";
 import { useCallback, useEffect, useReducer, useRef } from "react";
 import { initialWorkspaceState, workspaceReducer } from "./reducer";
 import {
@@ -289,7 +288,6 @@ export function useWorkspace() {
 					});
 			}
 		})();
-		const appWindow = getCurrentWindow();
 		const visibility = () =>
 			dispatch({
 				type: "setWindowActive",
@@ -310,7 +308,6 @@ export function useWorkspace() {
 			window.removeEventListener("blur", visibility);
 			document.removeEventListener("visibilitychange", visibility);
 			Object.values(timers.current).forEach(clearTimeout);
-			void appWindow;
 		};
 	}, [consumePromotedRuntime, refresh, scheduleSnapshot]);