feat(ocr): Implement persistent worker pool with SQLite job queue

Major OCR infrastructure improvements:
- Add persistent SQLite-based job queue for OCR tasks
- Implement worker pool with process isolation and auto-restart
- Add OCR engine selector dropdown (Tesseract/PaddleOCR) in upload zone
- Optimize Tesseract preprocessing based on benchmark results (8x faster)
- Add recognize_cif_optimized() with multi-strategy CIF extraction
- Add Romanian CIF checksum validation
- Increase Telegram long polling timeout from 10s to 30s

Squashed commits:
- feat(ocr): Implement persistent worker pool with SQLite job queue
- feat(ocr): Add OCR engine selector dropdown to upload zone
- perf(telegram): Increase long polling timeout from 10s to 30s
- perf(ocr): Optimize Tesseract preprocessing based on benchmark results

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

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

src/modules/data-entry/views/receipts/ReceiptCreateView.vue

@@ -987,33 +987,63 @@ const rescanAttachmentOCR = async (attachment) => {
     // Create a File object from the blob
     const file = new File([response.data], attachment.filename, { type: attachment.mime_type })
 
-    // Send to OCR
+    // Send to OCR job queue
     const formData = new FormData()
     formData.append('file', file)
 
-    const ocrResponse = await apiService.post('/ocr/extract', formData, {
-      headers: { 'Content-Type': 'multipart/form-data' },
-      timeout: 60000,
+    // Submit job
+    const submitResponse = await apiService.post('/ocr/extract', formData, {
+      timeout: 30000,
     })
 
-    if (ocrResponse.data.success) {
-      const resultData = {
-        ...ocrResponse.data.data,
-        _ocr_message: ocrResponse.data.message
+    const jobId = submitResponse.data.job_id
+    console.log('📋 OCR Rescan Job:', submitResponse.data)
+
+    // Poll for result
+    const maxAttempts = 120
+    let attempts = 0
+
+    while (attempts < maxAttempts) {
+      await new Promise(resolve => setTimeout(resolve, 1000)) // Wait 1 second
+
+      const pollResponse = await apiService.get(`/ocr/jobs/${jobId}`)
+      const job = pollResponse.data
+
+      if (job.status === 'completed') {
+        if (job.result) {
+          ocrData.value = {
+            ...job.result,
+            _processing_time_ms: job.processing_time_ms
+          }
+          ocrCollapsed.value = false
+          toast.add({
+            severity: 'success',
+            summary: 'OCR Procesare',
+            detail: 'Datele au fost re-extrase din atasament',
+            life: 3000,
+          })
+        }
+        break
       }
-      ocrData.value = resultData
-      ocrCollapsed.value = false
-      toast.add({
-        severity: 'success',
-        summary: 'OCR Procesare',
-        detail: 'Datele au fost re-extrase din atasament',
-        life: 3000,
-      })
-    } else {
+
+      if (job.status === 'failed') {
+        toast.add({
+          severity: 'error',
+          summary: 'Eroare OCR',
+          detail: job.error || 'Procesare OCR esuata',
+          life: 5000,
+        })
+        break
+      }
+
+      attempts++
+    }
+
+    if (attempts >= maxAttempts) {
       toast.add({
         severity: 'error',
         summary: 'Eroare OCR',
-        detail: ocrResponse.data.message || 'Procesare OCR esuata',
+        detail: 'Timeout - procesarea a durat prea mult',
         life: 5000,
       })
     }