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/db.js

@@ -648,7 +648,9 @@ try {
 } catch {
   db.prepare("ALTER TABLE dashboard_runs ADD COLUMN tool TEXT NOT NULL DEFAULT 'claude'").run();
 }
-// Which AI Router profile this lane runs against (see server/lib/ai-routers.js).
+// Which AI Proxy (then called AI Router) profile this lane ran against. Legacy:
+// a proxy is a session's choice now, and proxy-apply.js's clearLaneProxies
+// empties this column at every start.
 // Nullable, and null means the same thing as 'native': the vendor's own API.
 // Set at creation only — like `tool`, it is absent from lanes.js's PATCHABLE,
 // because the router is already written into the lane's config on disk and a
@@ -687,13 +689,19 @@ try {
   db.prepare("ALTER TABLE dashboard_runs ADD COLUMN worktree INTEGER NOT NULL DEFAULT 0").run();
 }
 
-// Migrate: add `router` to dashboard_runs — the AI Router profile the run was
-// started on (NULL = native). A router is chosen per session now, and a resume
-// that does not name one goes back to the router its session last ran on.
+// Migrate: add `proxy` to dashboard_runs — the AI Proxy profile the run was
+// started on (NULL = native). A proxy is chosen per session, and a resume that
+// does not name one goes back to the proxy its session last ran on. The column
+// was `router` before the AI Router → AI Proxy rename; it is renamed in place.
 try {
-  db.prepare("SELECT router FROM dashboard_runs LIMIT 1").get();
+  db.prepare("SELECT proxy FROM dashboard_runs LIMIT 1").get();
 } catch {
-  db.prepare("ALTER TABLE dashboard_runs ADD COLUMN router TEXT").run();
+  try {
+    db.prepare("SELECT router FROM dashboard_runs LIMIT 1").get();
+    db.prepare("ALTER TABLE dashboard_runs RENAME COLUMN router TO proxy").run();
+  } catch {
+    db.prepare("ALTER TABLE dashboard_runs ADD COLUMN proxy TEXT").run();
+  }
 }
 
 // Migrate: add stage-detection columns to lanes. Inference is never evidence —