feat(ocr): Add modular store profiles with hot-reload support

## Store Profiles System
- Add ProfileRegistry for CUI-based profile lookup
- Add BaseStoreProfile with generic extraction patterns
- Implement hot-reload via POST /api/data-entry/ocr/profiles/reload

## 12 Store Profiles
- LIDL: Multi-rate TVA (A, B, C, D codes)
- OMV, SOCAR: B2B with client CUI, YYYY.MM.DD dates
- BRICK, DEDEMAN: Standard TVA, e-factura support
- KINETERRA, BEST PRINT: Non-VAT payers (returns [])
- STEPOUT MARKET: TVA 5% (books/reduced rate)
- UNLIMITED KEYS: NUMERAR payment detection
- GAMA INK, ELECTROBERING, PICTUS VELUM: Standard TVA

## Flexible TVA Patterns
- All patterns use (\d{1,2})% to accept any rate
- Supports historical (19%, 9%, 5%) and current (21%, 11%)

## Payment Methods Fix
- Fixed base.py to support multiple payments of same type
- Changed deduplication from method-only to (method, amount) tuple
- Returns separate entries for split payments

## Tools
- Add generate_store_profile.py for automatic profile generation
- Analyzes PDFs via OCR API and detects patterns

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

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

.claude/rules/claude-learn-backend.md

@@ -0,0 +1,106 @@
+# Claude Learn: Backend
+
+**Domain**: backend
+**Last updated**: 2026-01-06
+**Sessions recorded**: 1
+
+Knowledge about FastAPI, Python services, Oracle DB, and backend architecture.
+
+---
+
+## Patterns
+
+### ProfileRegistry cu Hot-Reload pentru Store Profiles
+**Discovered**: 2026-01-06 (feature: ocr-store-profiles)
+**Description**: Sistem de înregistrare profile OCR folosind decorator `@ProfileRegistry.register` cu hot-reload via `importlib.reload()`. Permite adăugarea/modificarea profilelor fără restart server.
+
+**Example** (`backend/modules/data_entry/services/ocr/profiles/__init__.py`):
+```python
+class ProfileRegistry:
+    _profiles: Dict[str, Type["BaseStoreProfile"]] = {}
+    _instances: Dict[str, "BaseStoreProfile"] = {}
+
+    @classmethod
+    def register(cls, profile_class):
+        """Decorator to register a store profile class."""
+        for cui in profile_class.CUI_LIST:
+            cls._profiles[cls._normalize_cui(cui)] = profile_class
+        return profile_class
+
+    @classmethod
+    def reload_all(cls):
+        """Hot-reload all profile modules via importlib.reload()."""
+        cls._instances.clear()
+        for module_name in cls._get_profile_module_names():
+            importlib.reload(sys.modules[f"backend...profiles.{module_name}"])
+```
+
+**Usage**:
+```python
+@ProfileRegistry.register
+class LidlProfile(BaseStoreProfile):
+    CUI_LIST = ["22891860"]
+    STORE_NAME = "LIDL DISCOUNT S.R.L."
+
+# Lookup
+profile = ProfileRegistry.get_profile("22891860")
+
+# Hot-reload (endpoint)
+POST /api/data-entry/ocr/profiles/reload
+```
+
+**Tags**: registry-pattern, hot-reload, decorator, ocr, singleton
+
+---
+
+### Script generare cod Python din analiză PDF
+**Discovered**: 2026-01-06 (feature: ocr-store-profiles)
+**Description**: Script care analizează PDF-uri via OCR API, detectează pattern-uri (TVA format, date format, payment) și generează automat cod Python pentru profile noi. Include JWT auth, async polling, și verificare sintaxă.
+
+**Example** (`scripts/generate_store_profile.py`):
+```python
+def analyze_tva_patterns(results: List[Dict]) -> Dict:
+    """Detectează format TVA dominant din rezultatele OCR."""
+    tva_formats = defaultdict(int)
+    for text in raw_texts:
+        if re.search(r'TVA\s+[A-D]\s+\d{1,2}', text_upper):
+            tva_formats["lidl_multi_rate"] += 1
+        if re.search(r'BAZA\s+TVA', text_upper):
+            tva_formats["table"] += 1
+    return {"dominant_format": max(tva_formats, key=tva_formats.get)}
+
+def generate_profile_code(store_name, cui, tva_analysis, ...):
+    """Generează cod Python pentru clasa de profil."""
+    # Template-based generation cu OCR error variants
+```
+
+**Usage**:
+```bash
+# Dry-run pentru preview
+python scripts/generate_store_profile.py \
+  --name "Magazin Nou" --cui "12345678" \
+  --receipts "docs/data-entry/MagazinNou*.pdf" --dry-run
+
+# Generează și salvează
+python scripts/generate_store_profile.py \
+  --name "Magazin Nou" --cui "12345678" \
+  --receipts "docs/data-entry/MagazinNou*.pdf" \
+  --output backend/.../profiles/magazin_nou.py
+```
+
+**Tags**: code-generation, ocr, automation, cli-tool
+
+---
+
+## Gotchas
+
+_(None recorded yet)_
+
+---
+
+## Statistics
+
+- **Total Patterns**: 2
+- **Total Gotchas**: 0
+- **Last Session**: 2026-01-06
+- **Sessions Recorded**: 1