feat(pwa): static manifest, root-scoped worker, offline fallback

Add app/static/manifest.json (TimeTracker / Tracker, indigo theme) and PNG install icons via scripts/generate_pwa_icons.py.

Replace inline Flask service worker with app/static/js/sw.js served at /service-worker.js for full-site scope. Cache name timetracker-v1: cache-first for /static, network-first for HTML and non-v1 /api, no interception of /api/v1/* (preserves Authorization).

Add public GET /offline and offline.html for SW navigation fallback; redirect /manifest.webmanifest to the static manifest.

Wire base.html (manifest link, theme-color #4F46E5, SW registration) and pwa-enhancements.js (ready/update/push without duplicate registration). Remove legacy app/static/service-worker.js and manifest.webmanifest.

Tests: service worker and offline routes, manifest redirect, TestPWA expectations; drop duplicate test_enhanced_ui app/client fixtures in favor of conftest.

Docs: ASSETS.md, BUILD_CONFIGURATION.md, implementation notes, and incomplete-features analysis updated for new paths.

docs/ASSETS.md

@@ -167,7 +167,10 @@ Some formats require manual conversion:
 - **Base template:** `app/templates/base.html`
 - **Login page:** `app/templates/auth/login.html`
 - **About page:** `app/templates/main/about.html`
-- **Manifest:** `app/static/manifest.webmanifest`
+- **PWA manifest:** `app/static/manifest.json` (linked from `base.html`; `GET /manifest.webmanifest` redirects here for compatibility)
+- **PWA service worker source:** `app/static/js/sw.js` (served at `GET /service-worker.js` for site-wide scope; registered from `base.html`)
+- **PWA offline fallback page:** `app/templates/offline.html` (`GET /offline`, public, cache-friendly)
+- **Install icons (PNG):** `app/static/images/android-chrome-192x192.png`, `android-chrome-512x512.png` — regenerate with `python3 scripts/generate_pwa_icons.py` after visual changes
 
 ### Desktop Application
 - **Main window:** `desktop/src/main/window.js`

docs/BUILD_CONFIGURATION.md

@@ -104,7 +104,7 @@ See `desktop/assets/README.md` for detailed instructions on generating icons fro
 The web application uses the logo as favicon:
 - Location: `app/static/images/timetracker-logo.svg`
 - Configured in: `app/templates/base.html`
-- Also used in PWA manifest: `app/static/manifest.webmanifest`
+- Also used in PWA manifest: `app/static/manifest.json` (see `scripts/generate_pwa_icons.py` for install icons)
 
 ## Build Optimization
 

docs/INCOMPLETE_IMPLEMENTATIONS_ANALYSIS.md

@@ -350,9 +350,9 @@ The dedicated PostHog feature-flag helper under `app/utils/` was **removed**. Re
 ### 2. Frontend Features
 
 #### 2.1 Service Worker
-- **File:** `app/static/service-worker.js`
-- **Status:** Basic implementation exists but may need enhancement for full PWA functionality.
-  **Priority:** Medium
+- **File:** `app/static/js/sw.js` (registered URL: `/service-worker.js`)
+- **Status:** PWA shell caching, offline page, and `/api/v1/*` pass-through are implemented; further enhancements (e.g. broader precache, background sync tuning) remain optional.
+  **Priority:** Low
 
 #### 2.2 Kiosk Mode
 - **File:** `app/routes/kiosk.py`

docs/features/LAYOUT_IMPROVEMENTS_COMPLETE.md

@@ -326,9 +326,10 @@ new DragDropManager(document.getElementById('sortable-list'), {
 - Offline page
 - Cache strategies
 
-**Files Created:**
-- `app/static/service-worker.js`
-- Updated `manifest.webmanifest`
+**Files Created / current layout:**
+- `app/static/js/sw.js` (service worker; registered as `/service-worker.js`)
+- `app/static/manifest.json` (PWA manifest; legacy `GET /manifest.webmanifest` redirects)
+- `app/templates/offline.html`, `GET /offline`
 
 **Features:**
 - ✅ Offline mode
@@ -584,10 +585,10 @@ window.onboardingManager.reset()
 
 ## 🔧 Configuration
 
-### Service Worker Cache Version
-Edit `service-worker.js`:
+### Service Worker cache name
+Edit `app/static/js/sw.js` and bump the cache constant when changing caching behavior (e.g. after breaking static asset changes):
 ```javascript
-const CACHE_VERSION = 'v1.0.0';
+const CACHE_NAME = 'timetracker-v1';
 ```
 
 ### Chart Default Colors

docs/implementation-notes/APPLICATION_REVIEW_2025.md

@@ -258,7 +258,7 @@ Routes → Services → Repositories → Models → Database
      - Lazy loading for routes
      - Image optimization
      - CDN for static assets
-     - Service worker caching (exists: `app/static/service-worker.js`)
+     - Service worker caching (`app/static/js/sw.js`, served at `/service-worker.js`)
 
 #### 🟡 Medium Priority
 

docs/implementation-notes/IMPLEMENTATION_COMPLETE_SUMMARY.md

@@ -48,7 +48,7 @@ All 16 planned improvements have been successfully implemented and tested. The T
 8. `app/static/enhanced-ui.js` - **950 lines** - Core enhanced functionality
 9. `app/static/charts.js` - **450 lines** - Chart management utilities
 10. `app/static/onboarding.js` - **380 lines** - Onboarding system
-11. `app/static/service-worker.js` - **400 lines** - PWA service worker
+11. `app/static/js/sw.js` - PWA service worker (served at `/service-worker.js`; replaces former `app/static/service-worker.js`)
 
 ### Documentation (3)
 12. `LAYOUT_IMPROVEMENTS_COMPLETE.md` - **800 lines** - Complete documentation
@@ -58,7 +58,7 @@ All 16 planned improvements have been successfully implemented and tested. The T
 14. `tests/test_enhanced_ui.py` - **350 lines** - Comprehensive test suite
 
 ### Configuration (1)
-15. Updated `app/static/manifest.webmanifest` - PWA manifest with shortcuts
+15. `app/static/manifest.json` - PWA web app manifest (`/manifest.webmanifest` redirects for old clients)
 
 ---