feat: v2.5.5 — AI Router renamed AI Proxy, reload onto new builds, update no longer spins

AI Proxy (was AI Router):
- server/lib/ai-proxies.js, proxy-apply.js, routes/ai-proxies.js mounted at
  /api/ai-proxies and the old /api/ai-routers; `router` still accepted on the
  start routes; profiles move to <CLAUDE_HOME>/agenthub-proxies/
- dashboard_runs.router renamed in place to proxy: an older build on the same
  DB fails on that column, so dev and prod sharing one DB update together
- a proxy's baseUrl stored as its root (a typed /v1 made /v1/v1/messages);
  Test probes Claude /v1/messages and Codex /v1/responses
- Settings → AI Proxy (/settings/ai-router redirects), ProxyPicker

Updates:
- every tab reloads onto the new UI build when its WebSocket reconnects to a
  server of another version (lib/newBuildReload.ts, once per version)
- Update now stops waiting on a plugin chain that failed or pulled nothing
  (the old server never goes down), and reloads as soon as a new version answers

Also:
- a pane whose command exits at once says so (EPANEEXITED) instead of
  "Command failed: tmux set-option … mouse on"
- the pane drag preview draws where the pane actually lands

client/src/App.tsx

@@ -71,6 +71,7 @@ import { useWebSocket } from "./hooks/useWebSocket";
 import { useNotifications } from "./hooks/useNotifications";
 import { eventBus } from "./lib/eventBus";
 import { copyOnCtrlShiftC } from "./lib/keys";
+import { reloadOnNewBuild } from "./lib/newBuildReload";
 import type { WSMessage } from "./lib/types";
 
 // The heavy pages (xterm, the diff viewer, the settings editors) load on first
@@ -132,6 +133,10 @@ export default function App() {
     return () => window.removeEventListener("vite:preloadError", onPreloadError);
   }, []);
 
+  // The server came back as a newer version (any tab, any way it was updated):
+  // load its UI build instead of leaving the user to press F5.
+  useEffect(() => reloadOnNewBuild(), []);
+
   // Ctrl+Shift+C is copy here (Linux terminal habit), not the browser's inspector.
   useEffect(() => {
     window.addEventListener("keydown", copyOnCtrlShiftC, true);