Open existing agents from links and the CLI (#2324)

* feat(desktop): open existing agents from links

Register a stable agent deep link and route it through the existing Desktop window. Add a matching CLI command that resolves the local server and activates the requested agent without creating or messaging it.

* fix(desktop): recover agent link delivery

packages/desktop/src/preload.ts

@@ -23,6 +23,13 @@ contextBridge.exposeInMainWorld("paseoDesktop", {
     ipcRenderer.invoke("paseo:invoke", command, args),
   getPendingOpenProject: () =>
     ipcRenderer.invoke("paseo:get-pending-open-project") as Promise<string | null>,
+  agentNavigation: {
+    ready: () =>
+      ipcRenderer.invoke("paseo:agent-navigation:ready") as Promise<{
+        serverId: string;
+        agentId: string;
+      } | null>,
+  },
   events: {
     on: (event: string, handler: EventHandler): Promise<() => void> => {
       const listener = (_ipcEvent: Electron.IpcRendererEvent, payload: unknown) => {