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/config.py

@@ -0,0 +1,51 @@
+# app/modules/loyalty/config.py
+"""
+Module configuration.
+
+Environment-based configuration using Pydantic Settings.
+Settings are loaded from environment variables with LOYALTY_ prefix.
+
+Example:
+    LOYALTY_DEFAULT_COOLDOWN_MINUTES=15
+    LOYALTY_MAX_DAILY_STAMPS=5
+    LOYALTY_GOOGLE_ISSUER_ID=3388000000012345678
+
+Usage:
+    from app.modules.loyalty.config import config
+    cooldown = config.default_cooldown_minutes
+"""
+from pydantic_settings import BaseSettings
+
+
+class ModuleConfig(BaseSettings):
+    """Configuration for loyalty module."""
+
+    # Default anti-fraud settings
+    default_cooldown_minutes: int = 15
+    max_daily_stamps: int = 5
+    pin_max_failed_attempts: int = 5
+    pin_lockout_minutes: int = 30
+
+    # Points configuration
+    default_points_per_euro: int = 10  # 10 points per euro spent
+
+    # Google Wallet
+    google_issuer_id: str | None = None
+    google_service_account_json: str | None = None  # Path to JSON file
+
+    # Apple Wallet
+    apple_pass_type_id: str | None = None
+    apple_team_id: str | None = None
+    apple_wwdr_cert_path: str | None = None  # Apple WWDR certificate
+    apple_signer_cert_path: str | None = None  # Pass signing certificate
+    apple_signer_key_path: str | None = None  # Pass signing key
+
+    # QR code settings
+    qr_code_size: int = 300  # pixels
+
+    model_config = {"env_prefix": "LOYALTY_"}
+
+
+# Export for auto-discovery
+config_class = ModuleConfig
+config = ModuleConfig()