feat(FN-2976): detect and display external Tailscale funnel tunnels in remo

Merges external Tailscale funnel detection (FN-2976) — adds types, detection logic, status inclusion, kill flow, and a dedicated UI panel for funnel processes started outside Fusion — alongside custom AI providers API routes and a new settings UI section (FN-2965).

Fusion-Task-Id: FN-2976

packages/dashboard/src/routes/register-settings-memory-routes.ts

@@ -494,18 +494,29 @@ export function registerSettingsMemoryRoutes(ctx: ApiRoutesContext, deps: Settin
       const restore = engine?.getRemoteTunnelRestoreDiagnostics();
 
       const activeProvider = tunnelStatus?.provider ?? settings.remoteAccess?.activeProvider ?? null;
+      const tunnelState = tunnelStatus?.state ?? "stopped";
       let cloudflaredAvailable: boolean | null = null;
       if (activeProvider === "cloudflare") {
         cloudflaredAvailable = await isCloudflaredAvailable();
       }
 
+      const externalTunnel = tunnelState === "stopped"
+        ? await engine?.detectExternalTunnel()
+        : null;
+
       res.json({
         provider: activeProvider,
-        state: tunnelStatus?.state ?? "stopped",
+        state: tunnelState,
         url: tunnelStatus?.url ?? null,
         lastError: tunnelStatus?.lastError?.message ?? null,
         lastErrorCode: tunnelStatus?.lastError?.code ?? null,
         cloudflaredAvailable,
+        externalTunnel: externalTunnel
+          ? {
+            provider: externalTunnel.provider,
+            url: externalTunnel.url,
+          }
+          : null,
         restore: restore ?? {
           outcome: "skipped",
           reason: "not_attempted",
@@ -634,6 +645,19 @@ export function registerSettingsMemoryRoutes(ctx: ApiRoutesContext, deps: Settin
     }
   });
 
+  router.post("/remote/tunnel/kill-external", async (req, res) => {
+    try {
+      const { engine } = await getProjectContext(req);
+      if (engine) {
+        await engine.killExternalTunnel();
+      }
+      res.json({ ok: true });
+    } catch (err: unknown) {
+      if (err instanceof ApiError) throw err;
+      rethrowAsApiError(err, "Failed to kill external remote tunnel");
+    }
+  });
+
   router.post("/remote/token/persistent/regenerate", async (req, res) => {
     try {
       const { store: scopedStore } = await getProjectContext(req);