feat(loyalty): implement complete loyalty module MVP

Add stamp-based and points-based loyalty programs for vendors with:

Database Models (5 tables):
- loyalty_programs: Vendor program configuration
- loyalty_cards: Customer cards with stamp/point balances
- loyalty_transactions: Immutable audit log
- staff_pins: Fraud prevention PINs (bcrypt hashed)
- apple_device_registrations: Apple Wallet push tokens

Services:
- program_service: Program CRUD and statistics
- card_service: Customer enrollment and card lookup
- stamp_service: Stamp operations with anti-fraud checks
- points_service: Points earning and redemption
- pin_service: Staff PIN management with lockout
- wallet_service: Unified wallet abstraction
- google_wallet_service: Google Wallet API integration
- apple_wallet_service: Apple Wallet .pkpass generation

API Routes:
- Admin: /api/v1/admin/loyalty/* (programs list, stats)
- Vendor: /api/v1/vendor/loyalty/* (stamp, points, cards, PINs)
- Public: /api/v1/loyalty/* (enrollment, Apple Web Service)

Anti-Fraud Features:
- Staff PIN verification (configurable per program)
- Cooldown period between stamps (default 15 min)
- Daily stamp limits (default 5/day)
- PIN lockout after failed attempts

Wallet Integration:
- Google Wallet: LoyaltyClass and LoyaltyObject management
- Apple Wallet: .pkpass generation with PKCS#7 signing
- Apple Web Service endpoints for device registration/updates

Also includes:
- Alembic migration for all tables with indexes
- Localization files (en, fr, de, lu)
- Module documentation
- Phase 2 interface and user journey plan

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

app/modules/loyalty/models/__init__.py

@@ -0,0 +1,55 @@
+# app/modules/loyalty/models/__init__.py
+"""
+Loyalty module database models.
+
+This is the canonical location for loyalty models. Module models are automatically
+discovered and registered with SQLAlchemy's Base.metadata at startup.
+
+Usage:
+    from app.modules.loyalty.models import (
+        LoyaltyProgram,
+        LoyaltyCard,
+        LoyaltyTransaction,
+        StaffPin,
+        AppleDeviceRegistration,
+        LoyaltyType,
+        TransactionType,
+    )
+"""
+
+from app.modules.loyalty.models.loyalty_program import (
+    # Enums
+    LoyaltyType,
+    # Model
+    LoyaltyProgram,
+)
+from app.modules.loyalty.models.loyalty_card import (
+    # Model
+    LoyaltyCard,
+)
+from app.modules.loyalty.models.loyalty_transaction import (
+    # Enums
+    TransactionType,
+    # Model
+    LoyaltyTransaction,
+)
+from app.modules.loyalty.models.staff_pin import (
+    # Model
+    StaffPin,
+)
+from app.modules.loyalty.models.apple_device import (
+    # Model
+    AppleDeviceRegistration,
+)
+
+__all__ = [
+    # Enums
+    "LoyaltyType",
+    "TransactionType",
+    # Models
+    "LoyaltyProgram",
+    "LoyaltyCard",
+    "LoyaltyTransaction",
+    "StaffPin",
+    "AppleDeviceRegistration",
+]