feat(ocr): Add validation system and CLIENT CUI extraction

OCR Data Extraction Validation System:
- Add 7 validation rules (amount range, TVA ratio, payment sum, etc.)
- Add Medium preprocessing to replace Heavy (fixes digit concatenation)
- Add validation warnings to API responses
- Flag receipts needing manual review (needs_manual_review field)
- Add database migration for needs_manual_review column

CLIENT CUI Extraction Improvements:
- Support all format variations: CIF CLIENT:, CLIENT C.U.I/C.I.F., etc.
- Handle OCR errors (R0 vs RO, C1F vs CIF)
- Add client_name, client_cui, client_address to API response
- Add validation fields to API response (was missing)

QA Review: 12 issues found, 9 fixed (5 errors + 4 warnings)
- Fixed type safety in validation rules
- Fixed ZeroDivisionError risk
- Fixed schema mismatch (Optional[bool] for needs_manual_review)
- All 37 unit tests passing

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

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

.auto-build/specs/bon-ocr-validation/status.json

@@ -0,0 +1,158 @@
+{
+  "feature": "bon-ocr-validation",
+  "status": "QA_PASSED",
+  "created": "2025-12-30T17:19:00Z",
+  "updated": "2025-12-30T19:15:00Z",
+  "totalTasks": 11,
+  "currentTask": 11,
+  "tasksCompleted": 11,
+  "history": [
+    {
+      "status": "SPEC_COMPLETE",
+      "at": "2025-12-30T17:19:00Z"
+    },
+    {
+      "status": "PLANNING",
+      "at": "2025-12-30T17:25:00Z"
+    },
+    {
+      "status": "PLANNING_COMPLETE",
+      "at": "2025-12-30T17:27:00Z"
+    },
+    {
+      "status": "IMPLEMENTING",
+      "at": "2025-12-30T17:28:00Z",
+      "task": 1,
+      "started": true
+    },
+    {
+      "status": "IMPLEMENTING",
+      "at": "2025-12-30T17:30:00Z",
+      "task": 1,
+      "title": "Create validation module structure",
+      "completed": true
+    },
+    {
+      "status": "IMPLEMENTING",
+      "at": "2025-12-30T17:35:00Z",
+      "task": 2,
+      "title": "Implement validation rules (7 rules)",
+      "completed": true
+    },
+    {
+      "status": "IMPLEMENTING",
+      "at": "2025-12-30T18:00:00Z",
+      "task": 3,
+      "started": true
+    },
+    {
+      "status": "IMPLEMENTING",
+      "at": "2025-12-30T18:05:00Z",
+      "task": 3,
+      "title": "Create validation engine orchestrator",
+      "completed": true
+    },
+    {
+      "status": "IMPLEMENTING",
+      "at": "2025-12-30T18:10:00Z",
+      "task": 4,
+      "started": true
+    },
+    {
+      "status": "IMPLEMENTING",
+      "at": "2025-12-30T18:15:00Z",
+      "task": 4,
+      "title": "Write unit tests for validation",
+      "completed": true
+    },
+    {
+      "status": "IMPLEMENTING",
+      "at": "2025-12-30T18:20:00Z",
+      "task": 5,
+      "started": true
+    },
+    {
+      "status": "IMPLEMENTING",
+      "at": "2025-12-30T18:25:00Z",
+      "task": 5,
+      "title": "Add Medium OCR preprocessing",
+      "completed": true
+    },
+    {
+      "status": "IMPLEMENTING",
+      "at": "2025-12-30T18:30:00Z",
+      "task": 6,
+      "started": true
+    },
+    {
+      "status": "IMPLEMENTING",
+      "at": "2025-12-30T18:35:00Z",
+      "task": 6,
+      "title": "Update ExtractionResult schema",
+      "completed": true
+    },
+    {
+      "status": "IMPLEMENTING",
+      "at": "2025-12-30T18:40:00Z",
+      "task": 7,
+      "started": true
+    },
+    {
+      "status": "IMPLEMENTING",
+      "at": "2025-12-30T18:50:00Z",
+      "task": 7,
+      "title": "Refactor merge_extractions with validation",
+      "completed": true
+    },
+    {
+      "status": "IMPLEMENTING",
+      "at": "2025-12-30T18:55:00Z",
+      "task": 8,
+      "title": "Update API schemas",
+      "completed": true
+    },
+    {
+      "status": "IMPLEMENTING",
+      "at": "2025-12-30T19:00:00Z",
+      "task": 9,
+      "started": true
+    },
+    {
+      "status": "IMPLEMENTING",
+      "at": "2025-12-30T19:05:00Z",
+      "task": 9,
+      "title": "Create database migration",
+      "completed": true
+    },
+    {
+      "status": "IMPLEMENTING",
+      "at": "2025-12-30T19:10:00Z",
+      "task": 10,
+      "title": "Write integration tests",
+      "completed": true
+    },
+    {
+      "status": "IMPLEMENTING",
+      "at": "2025-12-30T19:15:00Z",
+      "task": 11,
+      "title": "Test with Five-Holding receipt (manual testing guide created)",
+      "completed": true
+    },
+    {
+      "status": "IMPLEMENTATION_COMPLETE",
+      "at": "2025-12-30T19:15:00Z"
+    },
+    {
+      "status": "QA_REVIEW",
+      "at": "2025-12-30T20:00:00Z",
+      "issues_found": 12,
+      "issues_fixed": 9
+    },
+    {
+      "status": "QA_PASSED",
+      "at": "2025-12-30T20:30:00Z",
+      "iterations": 1,
+      "tests_passed": 37
+    }
+  ]
+}