feat(data-entry): Bulk Receipt Upload cu Mobile UX Android Nativ

## Funcționalități Principale

### Bulk Upload & Processing
- Drag & drop pentru upload bonuri multiple oriunde pe pagină
- Batch processing cu job queue și worker pool
- Real-time updates via SSE (Server-Sent Events) cu fallback polling
- Duplicate detection via SHA-256 file hash
- Auto-retry pentru job-uri failed
- Cancel individual jobs sau batch complet

### Mobile UX - Android Native Style
- Top bar fixă cu hamburger, titlu centrat, acțiuni (search/filter)
- Bottom navigation cu 4 tab-uri (Bonuri, Upload, Rapoarte, Setări)
- FAB (Floating Action Button) cu hide/show on scroll
- Filter chips orizontal scrollabile
- Selecție multiplă prin long-press (500ms)
- Select All + Bulk Delete cu confirmare
- Layout Android pentru Create/Edit/View bon (Gmail compose style)

### Bug Fixes
- Refresh individual via SSE în loc de refresh total pagină
- Bonurile cu eroare OCR rămân vizibile pentru editare manuală
- Afișare nume fișier original pentru toate bonurile
- Upload stabil pe mobil (fix race condition File API)
- Păstrare ordine bonuri la refresh (nu se reordonează)

### Backend
- SSE endpoint pentru status updates real-time
- Bulk delete endpoint cu partial success
- Auto-cleanup bonuri failed după 7 zile
- Batch model cu tracking complet

### Testing
- E2E tests cu Playwright
- Unit tests pentru bulk upload, auto-create, cleanup

## Commits Squashed: 43 user stories (US-001 → US-043)
## Branch: ralph/bulk-receipt-upload
## Timp dezvoltare: ~3 zile (Ralph autonomous)

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

backend/modules/data_entry/routers/__init__.py

@@ -13,6 +13,7 @@ def create_data_entry_router() -> APIRouter:
     - /nomenclature - Nomenclature syncing from Oracle
     - /settings - User settings (OCR preferences)
     - /metrics - OCR analytics and metrics
+    - /bulk - Bulk upload for batch processing
 
     Returns:
         APIRouter: Configured router for data entry module
@@ -24,6 +25,7 @@ def create_data_entry_router() -> APIRouter:
     from .ocr import router as ocr_router
     from .nomenclature import router as nomenclature_router
     from .ocr_settings import router as ocr_settings_router
+    from .bulk import router as bulk_router
 
     # Include all sub-routers (no prefix - already prefixed in main.py with /api/data-entry)
     router.include_router(receipts_router, prefix="/receipts", tags=["data-entry-receipts"])
@@ -31,5 +33,7 @@ def create_data_entry_router() -> APIRouter:
     router.include_router(nomenclature_router, prefix="/nomenclature", tags=["data-entry-nomenclature"])
     # OCR settings and metrics (endpoints at /settings/* and /metrics/*)
     router.include_router(ocr_settings_router, tags=["data-entry-settings"])
+    # Bulk upload for batch processing
+    router.include_router(bulk_router, prefix="/bulk", tags=["data-entry-bulk"])
 
     return router