The CI build-and-push-api job uses context: . (repo root), so all
COPY paths must be relative to the repo root, not the api/ directory.
Also installs ./common/ alongside the api package, matching the
receiptwitness Dockerfile pattern.
Co-Authored-By: Paperclip <noreply@paperclip.ing>
Adds alembic.ini and alembic/ directory to the production API image so
alembic upgrade head can run in-cluster as an init container.
Also carries migration 003 (make hashed_password nullable) from PR #66.
Co-Authored-By: Paperclip <noreply@paperclip.ing>