chore: improve tooling, linting, testing, and CI

- Add LICENSE file (CC BY-NC-SA 4.0)
- Add .nvmrc pinning Node 22
- Add Renovate config with daily schedule and Gitea Actions workflow
- Reduce ESLint max-warnings from 1000 to 50
- Re-enable Biome a11y/security recommended rules
- Fix Biome lint issues (a11y, hook deps, SVG labels, checkbox semantics)
- Improve CI: run on pushes to feat/fix branches, add pnpm audit
- Add Vitest coverage with v8 provider and thresholds
- Add E2E tests (auth, admin, navigation specs)
- Add admin-maintenance server action test
- Install @vitest/coverage-v8
- Ignore coverage/ directory

public/sw.js

@@ -9,7 +9,9 @@ self.addEventListener("activate", (event) => {
 			.keys()
 			.then((keys) =>
 				Promise.all(
-					keys.filter((k) => k !== CACHE && k !== API_CACHE).map((k) => caches.delete(k)),
+					keys
+						.filter((k) => k !== CACHE && k !== API_CACHE)
+						.map((k) => caches.delete(k)),
 				),
 			)
 			.then(() => self.clients.claim()),