feat: Improve OCR adaptive pipeline with early exit and better pattern matching

- Add adaptive 3-step OCR pipeline with early exit when all 5 fields found
- Add pattern for "C. I. F." with spaces (OCR artifact from PaddleOCR)
- Add pattern for YYYY. MM. DD date format with spaces (OMV/Petrom receipts)
- Add pattern for "OTAL TAXE" with T cut off and reversed amount position
- Make TVA rate pattern more flexible (code letter optional, handle "-21%")
- Replace logger.info with print(flush=True) for better debugging visibility
- Improve OCRPreview.vue to show extraction progress and raw OCR text

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

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

data-entry-app/backend/app/routers/ocr.py

@@ -102,6 +102,8 @@ async def extract_from_image(file: UploadFile = File(...)):
             confidence_vendor=result.confidence_vendor,
             overall_confidence=result.overall_confidence,
             raw_text=result.raw_text,
+            ocr_engine=result.ocr_engine,
+            processing_time_ms=result.processing_time_ms,
         )
 
         return OCRResponse(success=True, message=message, data=data)
@@ -171,6 +173,8 @@ async def extract_from_attachment(
         confidence_vendor=result.confidence_vendor,
         overall_confidence=result.overall_confidence,
         raw_text=result.raw_text,
+        ocr_engine=result.ocr_engine,
+        processing_time_ms=result.processing_time_ms,
     )
 
     return OCRResponse(success=True, message=message, data=data)