Previously a missing master.xprv.enc only surfaced as a 500 on the
first register call, with a stack trace that didn't say what to do
about it. Check for the file before alembic/uvicorn start and exit 1
with the exact generate_master_key.py command to run.
Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>
python:3.12-slim, installs the package (pip install .), runs pending
Alembic migrations before starting uvicorn. Migrations/alembic.ini/
scripts are copied in as-is (not part of the installed package) since
alembic and generate_master_key.py run directly against the source
tree.
Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>