feat(ui,server): surface active instance service URLs in About settings (#2669)

Show the running instance's local server URL and tunnel URL (when a
tunnel is active) as labeled, click-to-open buttons on the About page.
/api/system/info now reports the instance port and tunnel URL, resolved
lazily from the tunnel runtime so each Git-worktree instance identifies
itself in the UI without parsing terminal output.

Refs OPE-194

packages/web/server/lib/opencode/core-routes.js

@@ -67,6 +67,12 @@ export const registerServerStatusRoutes = (app, dependencies) => {
     serverStartedAt,
     gracefulShutdown,
     getHealthSnapshot,
+    // Port this OpenChamber instance serves on and the tunnel public URL (if
+    // a tunnel is active). Exposed on /api/system/info so the UI can surface
+    // the active instance's service URLs. Optional: older wiring omits them
+    // and the endpoint reports null.
+    getServerPort = () => null,
+    getTunnelUrl = () => null,
     // Stable server identity (hash of the public signing key — not a secret).
     // Exposed on /health and /api/version so a client can verify that a
     // learned/probed address belongs to the expected server BEFORE sending its
@@ -356,6 +362,8 @@ export const registerServerStatusRoutes = (app, dependencies) => {
       runtime: runtimeName,
       pid: process.pid,
       startedAt: serverStartedAt,
+      port: getServerPort(),
+      tunnelUrl: getTunnelUrl(),
     });
   });