Use the frozen uv lock for Cloud Run images

[anth-volk]

Fixes #3858

Summary

• install the API v1 Cloud Run environment with uv sync --frozen --no-dev --no-editable
• include uv.lock in the image build context and install the runtime environment into /opt/venv
• pin the uv container image used during image construction
• refresh uv.lock after CI increments the project version and before it commits the release changelog
• add a focused regression test that prevents the Cloud Run image from returning to pip resolution

Why

The Cloud Run image previously ran pip install -e . against dependency ranges and ignored uv.lock. The latest failed staging image therefore installed FastAPI 0.142.0 while the repository lock selected 0.138.2. FastAPI 0.142.0 attempted automatic OpenTelemetry configuration during startup and the application process exited.

Using the same frozen uv installation command as the simulation entry Cloud Run service makes the reviewed lock file determine the production dependency set.

Testing

• uv run --frozen pytest tests/unit/test_cloud_run_deploy_scripts.py tests/unit/test_asgi_factory.py -q (150 passed)
• uv run --frozen pytest tests/unit/test_alembic_workflows.py tests/unit/test_cloud_run_deploy_scripts.py -q (125 passed)
• uv run --frozen ruff check tests/unit/test_cloud_run_deploy_scripts.py
• uv lock --check
• docker build --platform linux/amd64 -f gcp/cloud_run/Dockerfile -t policyengine-api-cloud-run:uv-lock-test .
• verified /opt/venv/bin/python, Gunicorn, Uvicorn, policyengine-api 4.2.4, FastAPI 0.138.2, and policyengine-observability 3.0.1 inside the built image

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 87.65%. Comparing base (8468a86) to head (21d8790).

Additional details and impacted files

@@             Coverage Diff             @@
##           master    #3859       +/-   ##
===========================================
+ Coverage   45.76%   87.65%   +41.89%     
===========================================
  Files         182      197       +15     
  Lines       10812    11952     +1140     
  Branches     1837     2092      +255     
===========================================
+ Hits         4948    10477     +5529     
+ Misses       5456      901     -4555     
- Partials      408      574      +166     

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