feat(ops): add /healthz endpoint and container healthcheck

Expose a lightweight /healthz route on the main aiohttp server and
wire docker-compose healthcheck so orchestrators can detect failures.

bot/app/web/web_server.py

@@ -58,6 +58,11 @@ async def build_and_start_web_app(
     app = web.Application()
     _inject_shared_instances(app, dp, bot, settings, async_session_factory)
 
+    async def _healthcheck(request: web.Request) -> web.Response:
+        return web.json_response({"status": "ok"})
+
+    app.router.add_get("/healthz", _healthcheck)
+
     setup_application(app, dp, bot=bot)
 
     telegram_uses_webhook_mode = bool(settings.WEBHOOK_BASE_URL)

docker-compose.yml

@@ -14,6 +14,12 @@ services:
     ports:
       - 127.0.0.1:8080:8080
       - 127.0.0.1:${WEBAPP_SERVER_PORT:-8081}:${WEBAPP_SERVER_PORT:-8081}
+    healthcheck:
+      test: ["CMD-SHELL", "wget -qO- http://127.0.0.1:8080/healthz >/dev/null || exit 1"]
+      interval: 30s
+      timeout: 5s
+      retries: 5
+      start_period: 30s
 
   remnawave-tg-shop-db:
     image: postgres:17