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

src/lib/auth.ts

@@ -60,7 +60,10 @@ export const { handlers, signOut, auth } = NextAuth({
 	pages: { signIn: "/login", error: "/login" },
 	logger: {
 		error(error) {
-			logger.error("NextAuth error", { error: error.message, stack: error.stack });
+			logger.error("NextAuth error", {
+				error: error.message,
+				stack: error.stack,
+			});
 		},
 	},
 	providers: [