feat: Add JWT auth and nomenclature sync to data-entry-app

Integrate shared JWT authentication into data-entry-app:
- Add Oracle pool initialization for auth service
- Add AuthenticationMiddleware to protect API routes
- Update all receipt endpoints to use CurrentUser from JWT
- Add shared auth router (/api/auth/login, /api/auth/refresh)

Add nomenclature synchronization feature:
- Create SQLite models for synced suppliers, local suppliers, and cash registers
- Add nomenclature router with sync triggers and CRUD endpoints
- Add sync service for Oracle → SQLite nomenclature data
- Update nomenclature_service to use synced SQLite data with fallbacks

Create shared frontend components:
- Add shared/frontend/ with LoginView.vue, auth store factory, login.css
- Integrate shared login and auth into data-entry-app frontend
- Add axios-based API service with token refresh interceptor

🤖 Generated with [Claude Code](https://claude.com/claude-code)

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

data-entry-app/backend/app/db/models/__init__.py

@@ -1,6 +1,7 @@
 # Database models
 from .receipt import Receipt, ReceiptAttachment, ReceiptStatus, ReceiptType, ReceiptDirection
 from .accounting_entry import AccountingEntry, EntryType
+from .nomenclature import SyncedSupplier, LocalSupplier, SyncedCashRegister
 
 __all__ = [
     "Receipt",
@@ -10,4 +11,7 @@ __all__ = [
     "ReceiptDirection",
     "AccountingEntry",
     "EntryType",
+    "SyncedSupplier",
+    "LocalSupplier",
+    "SyncedCashRegister",
 ]