diff --git a/app/engines/piper.py b/app/engines/piper.py
index 8f7e819..b05d953 100644
--- a/app/engines/piper.py
+++ b/app/engines/piper.py
@@ -29,7 +29,7 @@ class PiperEngine(TTSEngineBase):
 
     def _load_config(self, model: str):
         """Load the model config JSON file to get speaker mappings."""
-        model_dir = f"./app/models/piper/{model}"
+        model_dir = f"/models/piper/{model}"
         config_file = os.path.join(model_dir, f"{model}.onnx.json")
         if os.path.isfile(config_file):
             with open(config_file, 'r') as f:
@@ -60,7 +60,7 @@ class PiperEngine(TTSEngineBase):
             raise RuntimeError("Piper executable not found. Please install it and ensure it's in your PATH.")
         if not model:
             raise ValueError("Model must be specified for Piper.")
-        model_dir = f"./app/models/piper/{model}"
+        model_dir = f"/models/piper/{model}"
         model_file = os.path.join(model_dir, f"{model}.onnx")
         if not os.path.isfile(model_file):
             raise FileNotFoundError(f"Piper model not found: {model_file}")
@@ -108,7 +108,7 @@ class PiperEngine(TTSEngineBase):
         return output_other_path
 
     def list_models(self):
-        models_dir = "./app/models/piper/"
+        models_dir = "/models/piper/"
         if not os.path.isdir(models_dir):
             return []
         return [name for name in os.listdir(models_dir)
diff --git a/docker-compose.yml b/docker-compose.yml
index 26529d4..5566d51 100644
--- a/docker-compose.yml
+++ b/docker-compose.yml
@@ -8,8 +8,8 @@ services:
     volumes:
       # Mount local app directory for hot-reloading in dev
       - ./app:/home/appuser/app
-      # Mount models directory to provide models to the container
-      - ./models:/home/appuser/app/models
+      # Mount models directory to a top-level directory in the container
+      - ./app/models:/models
       # Mount asset directory to persist generated audio files
       - ./asset:/home/appuser/app/asset
     command: ["uvicorn", "app.main:app", "--host", "0.0.0.0", "--port", "8000", "--reload"]
diff --git a/session_resumee.md b/session_resumee.md
index f01682b..a855681 100644
--- a/session_resumee.md
+++ b/session_resumee.md
@@ -89,6 +89,30 @@ The project was a modular FastAPI-based TTS server with a `TTSEngineBase` interf
 
 ---
 
-**Next Steps (Troubleshooting the 404):**
+### Final Debugging & Resolution (Post-Refactoring)
 
-The `404 page not found` when accessing `http://localhost/health` via Traefik is the current blocker for full verification. I need to investigate the logs of the `audio-engine-hub_app` container (the FastAPI app) to determine if the application itself is starting correctly and serving the `/health` endpoint as expected. If the app is indeed serving, the issue lies with Traefik's routing configuration.
+After the major refactoring, the service was unable to start and was returning `404` errors. The final debugging session addressed these issues.
+
+1.  **FastAPI App Startup Fix:**
+    *   **Problem:** The Uvicorn server was failing with `Attribute "app" not found in module "app.main"`.
+    *   **Solution:** The `app` instance was only created inside the `if __name__ == "__main__"` block. Moved `app = create_app()` to the module's global scope in `app/main.py` so Uvicorn could find it.
+
+2.  **Traefik & Docker Compose Issues:**
+    *   **Problem:** The initial `docker-compose.yml` included a Traefik service for reverse proxying, which was causing multiple issues (invalid container names due to missing `.env` variables, Docker client API version errors). The user also clarified that they use an existing reverse proxy and did not want a new Traefik container deployed.
+    *   **Solution:** Removed the `traefik` service entirely from `docker-compose.yml`. The `app` service's port was exposed directly to the host.
+
+3.  **Model Loading Failure:**
+    *   **Problem:** The `piper` engine was not loading any models, returning an empty list and causing `/tts` requests to fail with a `422 Unprocessable Entity` error.
+    *   **Diagnosis:** The root cause was an incorrect volume mount. The `docker-compose.yml` was attempting to mount a non-existent, empty `./models` directory from the host. The actual models were located in `./app/models`.
+    *   **Solution:**
+        1.  Corrected the `docker-compose.yml` volume mount to point to the correct source directory: `- ./app/models:/models`.
+        2.  Updated the `app/engines/piper.py` code to use the absolute path `/models/piper/` to look for models inside the container, making the configuration more robust and independent of the working directory.
+
+4.  **Developer Experience (DX) Improvements:**
+    *   **Automatic Port Finding:** The `Makefile` was enhanced. The `make up` and `make run` commands now automatically find a free port starting from 8000, preventing port conflicts.
+    *   **Health Check Command:** A `make health-check` target was added. It runs a sanity check against the deployed container's `/health` endpoint to verify that the service is up and all engines are reporting an "ok" status.
+    *   **Documentation:**
+        *   The `README.md` was completely rewritten to provide a clear and up-to-date guide for getting started, usage, and available `make` commands.
+        *   A note was added to `docs/guide.md` to clarify that it describes an older, more advanced setup and to point readers to the new `README.md`.
+
+**Final Status:** The service is now fully deployable via `make up` and passes `make health-check`. All identified startup issues and bugs have been resolved.
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