fix(gtea): ruff format + check all gtea files and bridge.py

Clears cc-ci self-test lint failures:
- ruff format: 9 files reformatted (all gtea test files + test_discovery.py)
- ruff check --fix: bridge.py UP017 (datetime.UTC alias) + 6 gtea check errors
- manifest.py B007: rename unused loop variable path → _path (no auto-fix available)

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

tests/gitea/recipe_meta.py

@@ -35,6 +35,7 @@ def READY_PROBE(ctx):
 def SCREENSHOT(page, ctx):
     # Navigate to the sign-in page — a credential-free view that shows the gitea UI.
     from playwright.sync_api import sync_playwright  # noqa: F401 — re-entry guard
+
     page.goto(f"{ctx.base_url}/user/login", wait_until="networkidle", timeout=30_000)
     page.wait_for_selector("form.ui.form", timeout=15_000)