refactor: Update CI configuration and local setup documentation; remove obsolete currency migration scripts

docs/architecture/14_testing_ci.md

@@ -21,7 +21,7 @@ CalMiner uses a combination of unit, integration, and end-to-end tests to ensure
 ### CI/CD
 
 - Use Gitea Actions for CI/CD; workflows live under `.gitea/workflows/`.
-- `test.yml` runs on every push with cached Python dependencies via `actions/cache@v3`.
+- `test.yml` runs on every push, provisions a temporary Postgres 16 service, waits for readiness, executes the setup script in dry-run and live modes, installs Playwright browsers, and finally runs the full pytest suite.
 - `build-and-push.yml` builds the Docker image with `docker/build-push-action@v2`, reusing GitHub Actions cache-backed layers, and pushes to the Gitea registry.
 - `deploy.yml` connects to the target host (via `appleboy/ssh-action`) to pull the freshly pushed image and restart the container.
 - Mandatory secrets: `REGISTRY_USERNAME`, `REGISTRY_PASSWORD`, `REGISTRY_URL`, `SSH_HOST`, `SSH_USERNAME`, `SSH_PRIVATE_KEY`.
@@ -99,10 +99,11 @@ pytest tests/e2e/ --headed
 `test.yml` encapsulates the steps below:
 
 - Check out the repository and set up Python 3.10.
-- Restore the pip cache (keyed by `requirements.txt`).
-- Install project dependencies and Playwright browsers (if needed for E2E).
+- Configure the runner's apt proxy (if available), install project dependencies (requirements + test extras), and download Playwright browsers.
 - Run `pytest` (extend with `--cov` flags when enforcing coverage).
 
+> The pip cache step is temporarily disabled in `test.yml` until the self-hosted cache service is exposed (see `docs/ci-cache-troubleshooting.md`).
+
 `build-and-push.yml` adds:
 
 - Registry login using repository secrets.