The `raw-stream` example files to build

[PetrNovota]

oakctl app run . fails with

App output:
    [2025-11-13T11:09:27Z] Traceback (most recent call last):
    [2025-11-13T11:09:27Z]   File "/app/main.py", line 13, in <module>
    [2025-11-13T11:09:27Z]     frontend_server = FrontendServer(IP, PORT, FRONTEND_DIRECTORY)
    [2025-11-13T11:09:27Z]                       ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
    [2025-11-13T11:09:27Z]   File "/app/frontend_server.py", line 15, in __init__
    [2025-11-13T11:09:27Z]     self._ensure_directory()
    [2025-11-13T11:09:27Z]   File "/app/frontend_server.py", line 21, in _ensure_directory
    [2025-11-13T11:09:27Z]     raise FileNotFoundError(
    [2025-11-13T11:09:27Z] FileNotFoundError: Failed to start the HTTP server. File index.html not found in the /app/frontend/dist folder.

``

[klemen1999]

Did you perform the prerequsite steps(listed under Usage section) of building the FE before starting the app?

1. Install FE dependencies: cd frontend/ && npm i
2. Build the FE: npm run build
3. Move back to origin directory: cd ..