Deploy push relay: dev-shell tooling, real relay URL, /health route

- flake.nix: add nodejs_22, firebase-tools, and google-cloud-sdk to the dev
  shell so the relay can be tested, built, deployed, and administered locally
- backend settings: point default_relay_url at the deployed relay
- rename the relay liveness route /healthz -> /health: Google Front End
  reserves /healthz and returns its own 404 before the request reaches Cloud
  Run, so the probe was unreachable (verified live; /v1/push and the FCM path
  work end-to-end)

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

TODO.md

@@ -24,7 +24,7 @@
 
 ## Frontend
 
-- [ ] In the status screen, the "listening for" property of passive scanners should change to days and months (now its always minutes)
+- [x] In the status screen, the "listening for" property of passive scanners should change to days and months (now its always minutes)
 - [ ] Check for potential dependency upgrades
 - [ ] In settings, figure out automatic save
 

backend/src/settings.rs

@@ -182,7 +182,7 @@ fn default_relay_url() -> String {
     // enable push: with `method = "push"` and no `[notifications.push]` section, this default is
     // used. The concrete URL is filled in once the relay Cloud Function is deployed (see
     // push_relay/README.md); a self-hoster can always override it via `relay_url`.
-    "https://oott-push-relay.example.com/v1/push".to_string()
+    "https://relay-dzhbmmulaq-uc.a.run.app/v1/push".to_string()
 }
 
 #[derive(Debug, Deserialize, Clone)]
@@ -623,7 +623,10 @@ mod tests {
         assert!(settings.notifications.push.is_none());
         assert!(settings.validate().is_ok());
         // The sender falls back to the default when the section is absent.
-        assert_eq!(settings.notifications.push.unwrap_or_default().relay_url, default_relay_url());
+        assert_eq!(
+            settings.notifications.push.unwrap_or_default().relay_url,
+            default_relay_url()
+        );
     }
 
     #[test]
@@ -652,7 +655,10 @@ mod tests {
             "
         );
         let settings = parse(&toml);
-        let push = settings.notifications.push.expect("push section should parse when present");
+        let push = settings
+            .notifications
+            .push
+            .expect("push section should parse when present");
         assert_eq!(push.relay_url, default_relay_url());
     }
 

flake.nix

@@ -69,6 +69,8 @@
           androidSdk
           jdk17
           nodejs_22 # push relay (push_relay/): runs npm install/test/build; bundles npm
+          firebase-tools # push relay: firebase CLI for emulator (serve) and deploy
+          google-cloud-sdk # push relay: gcloud for Cloud Run/IAM admin (e.g. invoker)
           claude-code
           clippy # Rust linter
           pythonEnv

push_notifications.md

@@ -97,7 +97,8 @@ Key properties:
     `firebase-admin` SDK
     (`messaging().sendEach(...)`, batched multicast) → return per-token results
     (`ok` / `unregistered` / `invalid`) so the caller can prune dead tokens.
-  - `GET /healthz` — liveness.
+  - `GET /health` — liveness. (Not `/healthz`: Google Front End reserves that
+    path and returns its own 404 before the request reaches the function.)
 - FCM client: the `firebase-admin` SDK authenticates via the function's runtime
   service account — **no service-account JSON to manage, no OAuth-token minting
   or caching code**. `sendEach` returns per-token success/error, giving us

push_relay/.firebaserc

@@ -0,0 +1,7 @@
+{
+  "projects": {
+    "default": "oott-push"
+  },
+  "targets": {},
+  "etags": {}
+}

push_relay/README.md

@@ -29,7 +29,8 @@ full design and rationale.
   "body": "..." } }`. Returns `{ "results": [{ "token": "...", "status":
   "ok" | "unregistered" | "invalid" | "error" }] }`. The backend prunes tokens
   reported `unregistered` or `invalid`.
-- `GET /healthz` — liveness, returns `200 ok`.
+- `GET /health` — liveness, returns `200 ok`. (Not `/healthz`: that path is
+  reserved by Google Front End and never reaches the function.)
 
 Protection (Phase 1, no shared secret): FCM project scoping (the relay can only
 reach OOTT app installs), per-source-IP rate limiting, and a billing cap.

push_relay/src/app.ts

@@ -30,8 +30,10 @@ export function createApp(deps: AppDependencies): Express {
   app.set("trust proxy", true);
   app.use(express.json({ limit: "256kb" }));
 
-  // Liveness probe — no side effects, never rate limited.
+  // Liveness probe — no side effects, never rate limited. Note: the path
-  app.get("/healthz", (_req: Request, res: Response) => {
+  // `/healthz` is reserved by Google Front End (it returns its own 404 before
+  // the request reaches Cloud Run), so this uses `/health`.
+  app.get("/health", (_req: Request, res: Response) => {
     res.status(200).send("ok");
   });
 

push_relay/src/index.ts

@@ -25,6 +25,6 @@ const rateLimitStore = createFirestoreRateLimitStore(
 
 const app = createApp({ messenger, rateLimitStore });
 
-// Single HTTP function hosting both routes (POST /v1/push, GET /healthz). Scales to zero, so there
+// Single HTTP function hosting both routes (POST /v1/push, GET /health). Scales to zero, so there
 // is no idle cost and no server/OS to patch; the platform provides TLS and a stable HTTPS URL.
 export const relay = onRequest({ region: "us-central1", maxInstances: 10 }, app);