Mobile notifications for iOS (#210)

* mobile: wire notification registration and listener

* implement backend components for push notifications

* refactor: agentic comment cleanup

* docs: use proper module name for particle processor

* set required env variables for push notifications

* bump version

* fix: always upsert push token on mobile start

* Revert "fix: always upsert push token on mobile start"

This reverts commit 90ff18a788.

* send push notifications regardless of online status

go/cmd/pusherservice/main.go

@@ -25,29 +25,22 @@ func main() {
 	port := utils.MustGetEnv("PORT")
 	grpcPort := utils.MustGetEnv("GRPC_PORT")
 
-	// Initialize database (for network membership checks)
 	db.Init()
 	defer db.Cleanup()
 
-	// Redis for auth session validation (same DB as orion)
-	authRedis := internal.ConnectAndTestRedis(db.RedisDBAuth)
+	authRedis := internal.ConnectAndTestRedis(db.RedisDBAuth)     // shared with orion
+	pusherRedis := internal.ConnectAndTestRedis(db.RedisDBPusher) // presence + pub/sub
 
-	// Redis for pusher state (presence hashes, pub/sub)
-	pusherRedis := internal.ConnectAndTestRedis(db.RedisDBPusher)
+	sessionReader := auth.NewSessionReader(authRedis)
+	networkReader := network.NewReader(db.Pool())
 
-	// Services
-	sessionReader := auth.NewSessionReader(authRedis) // pusher only validates sessions
-	networkReader := network.NewReader(db.Pool())     // pusher only checks membership
-
-	// Pod identity (use hostname in k8s, which is the pod name)
+	// Hostname is the k8s pod name.
 	podID, err := os.Hostname()
 	if err != nil {
 		podID = fmt.Sprintf("pod-%d", os.Getpid())
 	}
 
-	// Pusher core
 	bridge := pusher.NewRedisBridge(pusherRedis, podID)
-	// Context for graceful shutdown
 	ctx, cancel := context.WithCancel(context.Background())
 	defer cancel()
 
@@ -56,16 +49,11 @@ func main() {
 	bridge.SetHub(hub)
 	server := pusher.NewServer(ctx, hub, bridge, sessionReader)
 
-	// Start hub event loop
 	go hub.Run(ctx)
-
-	// Start Redis Pub/Sub listener
 	go bridge.Listen(ctx)
-
-	// Start pod heartbeat + stale pod cleanup
 	go bridge.Heartbeat(ctx)
 
-	// --- gRPC server (internal, for presence queries) ---
+	// --- gRPC server (internal presence queries) ---
 	grpcListener, err := net.Listen("tcp", fmt.Sprintf("0.0.0.0:%s", grpcPort))
 	if err != nil {
 		slog.Error("failed to listen for gRPC", "port", grpcPort, "error", err)
@@ -104,7 +92,7 @@ func main() {
 	<-sigCh
 
 	slog.Info("shutting down...")
-	cancel() // stops hub, bridge listener, heartbeat
+	cancel()
 
 	grpcServer.GracefulStop()
 	httpServer.Shutdown(context.Background())