perf: speed up local test runs by moving coverage to optional script

Run vitest without coverage by default (pnpm test) and add pnpm test:coverage which enforces the coverage thresholds. CI keeps using the coverage run so thresholds are still enforced on every push.

.gitea/workflows/container.yaml

@@ -18,7 +18,7 @@ jobs:
           pnpm install --frozen-lockfile
           pnpm typecheck
           pnpm biome:lint
-          pnpm test
+          pnpm test:coverage
         env:
           SKIP_ENV_VALIDATION: 1
           NODE_ENV: test