Stage 57 — PWA Network & Connection Resilience

One-stage test for PWA network timeout/fallback, connection status and public-cache resilience. No database changes and no SQL import.

1. PASS — PWA cache version v9 is present.
2. PASS — Network timeout and offline navigation fallback are present.
3. PASS — Online/offline connection resilience status is present.
4. PASS — Public PWA cache health check is present.
5. PASS — API and private application routes remain excluded from PWA caching.