002d8fe196
The charm had no ``hooks/init``, so Carbone started in its default stateless mode: no Studio, no template management, and ``CARBONE_BIND`` defaulting to ``127.0.0.1`` (unreachable behind the web-proxy). Add ``hooks/init`` to: - bind on ``0.0.0.0`` so the ``web-proxy`` can reach the service ; - serve the Studio and ``/carbone-studio.js`` (``CARBONE_STUDIO``) ; - enable stateful template management (``CARBONE_TEMPLATE_MANAGEMENT``): stable 64-bit template IDs, versioning and the ``/template`` endpoints ; - align the datastore/configstore ownership on the unprivileged ``carbone`` image user, otherwise the container crash-loops with ``EACCES`` on ``/app/config/config.json``. Persist ``/app/config`` as a ``config-resources`` and set a ``docker-compose.stop_grace_period`` of 200s: Carbone flushes its template metadata on graceful shutdown, and Docker's 10s default would SIGKILL it and lose templates on redeploy. Flush metadata every 5 minutes to shrink the hard-crash window. Bump the image to ``full-5.15.1`` and add a local ``basic-deploy`` test. Verified locally: ``/status`` 200, ``/carbone-studio.js`` 200, ``GET /templates`` 200, template upload with versioning plus render from the stable template ID, and metadata survival across a container recreation.