feat(events): route all backend events through a single event bus and store

Adds src/services/bus (the only listen/emit site: one handler per contract
event plus the frontend-internal test-all event) and the React
context/reducer app store. Migrates the five scattered subscriptions
(layout events, pending failures, proxy refresh, profile update/timer,
test-all), deletes the old glue (events.ts, use-listen, use-layout-events,
LoadingCacheProvider), moves run state into the store, and adds an
architecture gate script wired into CI. Behavior is unchanged; the
run-state query's poll/focus safety net is preserved by the store
provider.

src-tauri/src/core/notify/notification.rs

@@ -347,11 +347,7 @@ fn sample_frontend_events(uid: &String) -> Vec<(FrontendEvent<'_>, &'static str,
             "verge://refresh-verge-config",
             json!("yes"),
         ),
-        (
-            FrontendEvent::RefreshProfiles,
-            "verge://refresh-profiles",
-            json!("yes"),
-        ),
+        (FrontendEvent::RefreshProfiles, "verge://refresh-profiles", json!("yes")),
         (
             FrontendEvent::RefreshProxyConfig,
             "verge://refresh-proxy-config",