Add authenticated global economic calendar with Jin10 fallback

Collect macroeconomic releases, events and holidays through the official browser SDK with resumable history from 2025. Preserve evidence, revisions and observation times, and merge verified series with official fields taking priority.

Add category filters, field provenance, coverage and connection status. Verify calendar persistence and deployment recovery in isolated acceptance checks.

deploy/Dockerfile.backend

@@ -11,6 +11,8 @@ FROM base AS check
 RUN uv sync --locked && uv run pytest && uvx ruff==0.14.14 check --select F,E9,B src tests
 
 FROM base AS runtime
+ENV PLAYWRIGHT_BROWSERS_PATH=/opt/ms-playwright
+RUN playwright install --with-deps --only-shell chromium
 ARG APP_VERSION=source
 ARG APP_COMMIT=unknown
 ENV APP_VERSION=$APP_VERSION APP_COMMIT=$APP_COMMIT