feat(ocr): Add docTR OCR engine with metrics infrastructure

Add docTR as primary OCR engine with 2-tier sequential processing,
OCR metrics tracking, and simplified engine selection.

Features:
- docTR OCR engine with light+medium preprocessing tiers
- doctr_plus mode with early exit optimization (~65% fast path)
- OCR metrics dashboard with per-engine statistics
- User OCR preference persistence
- Parallel worker pool for OCR processing
- Cross-validation for extraction quality

Engine options: tesseract, doctr, doctr_plus (recommended), paddleocr

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

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

shared/auth/dependencies.py

@@ -109,15 +109,7 @@ async def get_current_user_from_request(request: Request) -> CurrentUser:
     Raises:
         HTTPException: Dacă utilizatorul nu este autentificat
     """
-    print(f"[DEPENDENCY DEBUG] get_current_user_from_request called")
-    print(f"[DEPENDENCY DEBUG] request.state attributes: {dir(request.state)}")
-    print(f"[DEPENDENCY DEBUG] has is_authenticated: {hasattr(request.state, 'is_authenticated')}")
-    print(f"[DEPENDENCY DEBUG] is_authenticated value: {getattr(request.state, 'is_authenticated', 'NOT_SET')}")
-    print(f"[DEPENDENCY DEBUG] has user: {hasattr(request.state, 'user')}")
-    print(f"[DEPENDENCY DEBUG] user value: {getattr(request.state, 'user', 'NOT_SET')}")
-    
     if not hasattr(request.state, 'is_authenticated') or not request.state.is_authenticated:
-        print(f"[DEPENDENCY DEBUG] Returning 401: Authentication required")
         raise HTTPException(
             status_code=status.HTTP_401_UNAUTHORIZED,
             detail="Authentication required",
@@ -125,14 +117,12 @@ async def get_current_user_from_request(request: Request) -> CurrentUser:
         )
     
     if not hasattr(request.state, 'user') or not request.state.user:
-        print(f"[DEPENDENCY DEBUG] Returning 401: User not found in request")
         raise HTTPException(
             status_code=status.HTTP_401_UNAUTHORIZED,
             detail="User not found in request",
             headers={"WWW-Authenticate": "Bearer"},
         )
-    
-    print(f"[DEPENDENCY DEBUG] Returning user: {request.state.user}")
+
     return request.state.user