Add Dockerfile for the app

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>

.dockerignore

@@ -0,0 +1,13 @@
+.venv/
+__pycache__/
+*.pyc
+.git/
+.env
+*.db
+master.xprv.enc
+logs/
+data/
+.pytest_cache/
+*.egg-info/
+tests/
+.claude/