Simplify tray: static template icon, click focuses the app

The setImage-swapped progress frames lost the template treatment on macOS and
rendered black-on-dark once transfers started. Dial back per user decision:
the tray is now just the glyph (template image set once at construction, never
swapped) and clicking it activates the window — no menu, no progress effects.
Removes everything that only served the fancy version: progress frames +
generation, engine.aggregateProgress, the workspacesSync webview->bun channel
(schema, send proxy, panels effect, handlers) and the activate-tab action.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

ui/src/app/panels.service.ts

@@ -1,4 +1,4 @@
-import { Injectable, computed, effect, signal, type WritableSignal } from '@angular/core';
+import { Injectable, computed, signal, type WritableSignal } from '@angular/core';
 import type { ConnectionConfig, FileEntry, SavedConnection } from '@shared/types';
 import { RpcService } from './rpc.service';
 import { ToastService } from './toast.service';
@@ -180,21 +180,6 @@ export class PanelsService {
   ) {
     this.newWorkspace();
 
-    // keep the bun-side tray informed about tabs (names, sessions, active)
-    if (this.rpc.available) {
-      effect(() => {
-        this.rpc.send.workspacesSync({
-          workspaces: this.workspaces().map((ws) => ({
-            id: ws.id,
-            name: this.workspaceName(ws),
-            remote: this.workspaceIsRemote(ws),
-            sessionIds: [ws.left.sessionId(), ws.right.sessionId()],
-          })),
-          activeId: this.activeWorkspaceId(),
-        });
-      });
-    }
-
     // a session died on its own — reset every panel bound to it, in any tab
     this.rpc.onSessionClosed((event) => {
       for (const workspace of this.workspaces()) {