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

server/lib/tmux.js

@@ -77,7 +77,18 @@ function envFlags(env) {
  */
 function newSession({ name, cwd, argv, env }) {
   execImpl(["new-session", "-d", "-s", name, "-c", cwd, ...envFlags(env), "--", ...argv]);
-  enableMouse(name);
+  try {
+    enableMouse(name);
+  } catch (err) {
+    // The pane's command exited at once (a CLI that refuses the terminal tmux
+    // gives it, say) and tmux closed the session with it: say that, not the
+    // "Command failed: tmux set-option …" that hid the real problem.
+    if (hasSession(name)) throw err;
+    throw Object.assign(
+      new Error(`the session's command exited as soon as it started: ${argv[0]}`),
+      { code: "EPANEEXITED" }
+    );
+  }
 }
 
 // Without this the pane has no scrollbar/drag scroll at all — wheel events