refactor: fix all architecture validator findings (202 → 0)

Eliminate all 103 errors and 96 warnings from the architecture validator:

Phase 1 - Validator rules & YAML:
- Add NAM-001/NAM-002 exceptions for module-scoped router/service files
- Fix API-004 to detect # public comments on decorator lines
- Add module-specific exception bases to EXC-004 valid_bases
- Exclude storefront files from AUTH-004 store context check
- Add SVC-006 exceptions for loyalty service atomic commits
- Fix _get_rule() to search naming_rules and auth_rules categories
- Use plain # CODE comments instead of # noqa: CODE for custom rules

Phase 2 - Billing module (5 route files):
- Move _resolve_store_to_merchant to subscription_service
- Move tier/feature queries to feature_service, admin_subscription_service
- Extract 22 inline Pydantic schemas to billing/schemas/billing.py
- Replace all HTTPException with domain exceptions

Phase 3 - Loyalty module (4 routes + points_service):
- Add 7 domain exceptions (Apple auth, enrollment, device registration)
- Add service methods to card_service, program_service, apple_wallet_service
- Move all db.query() from routes to service layer
- Fix SVC-001: replace HTTPException in points_service with domain exception

Phase 4 - Remaining modules:
- tenancy: move store stats queries to admin_service
- cms: move platform resolution to content_page_service, add NoPlatformSubscriptionException
- messaging: move user/customer lookups to messaging_service
- Add ConfigDict(from_attributes=True) to ContentPageResponse

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

app/modules/billing/schemas/billing.py

@@ -358,3 +358,192 @@ class FeatureCatalogResponse(BaseModel):
 
     features: dict[str, list[FeatureDeclarationResponse]]
     total_count: int
+
+
+# ============================================================================
+# Store Checkout Schemas
+# ============================================================================
+
+
+class PortalResponse(BaseModel):
+    """Customer portal session response."""
+
+    portal_url: str
+
+
+class CancelRequest(BaseModel):
+    """Request to cancel subscription."""
+
+    reason: str | None = None
+    immediately: bool = False
+
+
+class CancelResponse(BaseModel):
+    """Cancellation response."""
+
+    message: str
+    effective_date: str
+
+
+class UpcomingInvoiceResponse(BaseModel):
+    """Upcoming invoice preview."""
+
+    amount_due_cents: int
+    currency: str
+    next_payment_date: str | None = None
+    line_items: list[dict] = []
+
+
+class ChangeTierRequest(BaseModel):
+    """Request to change subscription tier."""
+
+    tier_code: str
+    is_annual: bool = False
+
+
+class ChangeTierResponse(BaseModel):
+    """Response for tier change."""
+
+    message: str
+    new_tier: str
+    effective_immediately: bool
+
+
+# ============================================================================
+# Store Subscription Schemas
+# ============================================================================
+
+
+class SubscriptionStatusResponse(BaseModel):
+    """Current subscription status."""
+
+    tier_code: str
+    tier_name: str
+    status: str
+    is_trial: bool
+    trial_ends_at: str | None = None
+    period_start: str | None = None
+    period_end: str | None = None
+    cancelled_at: str | None = None
+    cancellation_reason: str | None = None
+    has_payment_method: bool
+    last_payment_error: str | None = None
+    feature_codes: list[str] = []
+
+    class Config:
+        from_attributes = True
+
+
+class TierResponse(BaseModel):
+    """Subscription tier information."""
+
+    code: str
+    name: str
+    description: str | None = None
+    price_monthly_cents: int
+    price_annual_cents: int | None = None
+    feature_codes: list[str] = []
+    is_current: bool = False
+    can_upgrade: bool = False
+    can_downgrade: bool = False
+
+
+class TierListResponse(BaseModel):
+    """List of available tiers."""
+
+    tiers: list[TierResponse]
+    current_tier: str
+
+
+class InvoiceResponse(BaseModel):
+    """Invoice information."""
+
+    id: int
+    invoice_number: str | None = None
+    invoice_date: str
+    due_date: str | None = None
+    total_cents: int
+    amount_paid_cents: int
+    currency: str
+    status: str
+    pdf_url: str | None = None
+    hosted_url: str | None = None
+
+
+class InvoiceListResponse(BaseModel):
+    """List of invoices."""
+
+    invoices: list[InvoiceResponse]
+    total: int
+
+
+# ============================================================================
+# Store Feature Schemas
+# ============================================================================
+
+
+class FeatureCodeListResponse(BaseModel):
+    """Simple list of available feature codes for quick checks."""
+
+    features: list[str]
+    tier_code: str
+    tier_name: str
+
+
+class FeatureResponse(BaseModel):
+    """Full feature information."""
+
+    code: str
+    name: str
+    description: str | None = None
+    category: str
+    feature_type: str | None = None
+    ui_icon: str | None = None
+    is_available: bool
+
+
+class FeatureListResponse(BaseModel):
+    """List of features with metadata."""
+
+    features: list[FeatureResponse]
+    available_count: int
+    total_count: int
+    tier_code: str
+    tier_name: str
+
+
+class FeatureDetailResponse(BaseModel):
+    """Single feature detail with upgrade info."""
+
+    code: str
+    name: str
+    description: str | None = None
+    category: str
+    feature_type: str | None = None
+    ui_icon: str | None = None
+    is_available: bool
+    # Upgrade info (only if not available)
+    upgrade_tier_code: str | None = None
+    upgrade_tier_name: str | None = None
+    upgrade_tier_price_monthly_cents: int | None = None
+
+
+class CategoryListResponse(BaseModel):
+    """List of feature categories."""
+
+    categories: list[str]
+
+
+class FeatureGroupedResponse(BaseModel):
+    """Features grouped by category."""
+
+    categories: dict[str, list[FeatureResponse]]
+    available_count: int
+    total_count: int
+
+
+class StoreFeatureCheckResponse(BaseModel):
+    """Quick feature availability check response."""
+
+    has_feature: bool
+    feature_code: str