refactor: streamline routes to RESTful naming conventions

Remove /api/ prefix and consolidate route groups:
- /api/lobby/* -> /games, /snake, /logout (top-level)
- /game/{game_id} + /api/game/{game_id}/* -> /games/{id}/*
- /snake/{game_id} + /api/snake/{game_id}/* -> /snake/{id}/*
- /api/auth/* -> /auth/*
- Standardize snake join page to use return_url= (was return=)

features/c4game/routes.go

@@ -17,10 +17,9 @@ func SetupRoutes(
 	sessions *scs.SessionManager,
 	queries *repository.Queries,
 ) error {
-	router.Get("/game/{game_id}", HandleGamePage(store, sessions, queries))
-	router.Get("/game/{game_id}/events", HandleGameEvents(store, nc, sessions, queries))
-
-	router.Route("/api/game/{game_id}", func(r chi.Router) {
+	router.Route("/games/{id}", func(r chi.Router) {
+		r.Get("/", HandleGamePage(store, sessions, queries))
+		r.Get("/events", HandleGameEvents(store, nc, sessions, queries))
 		r.Post("/drop", HandleDropPiece(store, sessions))
 		r.Post("/chat", HandleSendChat(store, nc, sessions, queries))
 		r.Post("/join", HandleSetNickname(store, sessions))