refactor: migrate vendor APIs to token-based context and consolidate architecture

## Vendor-in-Token Architecture (Complete Migration)
- Migrate all vendor API endpoints from require_vendor_context() to token_vendor_id
- Update permission dependencies to extract vendor from JWT token
- Add vendor exceptions: VendorAccessDeniedException, VendorOwnerOnlyException,
  InsufficientVendorPermissionsException
- Shop endpoints retain require_vendor_context() for URL-based detection
- Add AUTH-004 architecture rule enforcing vendor context patterns
- Fix marketplace router missing /marketplace prefix

## Exception Pattern Fixes (API-003/API-004)
- Services raise domain exceptions, endpoints let them bubble up
- Add code_quality and content_page exception modules
- Move business logic from endpoints to services (admin, auth, content_page)
- Fix exception handling in admin, shop, and vendor endpoints

## Tailwind CSS Consolidation
- Consolidate CSS to per-area files (admin, vendor, shop, platform)
- Remove shared/cdn-fallback.html and shared/css/tailwind.min.css
- Update all templates to use area-specific Tailwind output files
- Remove Node.js config (package.json, postcss.config.js, tailwind.config.js)

## Documentation & Cleanup
- Update vendor-in-token-architecture.md with completed migration status
- Update architecture-rules.md with new rules
- Move migration docs to docs/development/migration/
- Remove duplicate/obsolete documentation files
- Merge pytest.ini settings into pyproject.toml

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

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

app/api/v1/vendor/customers.py

@@ -2,6 +2,8 @@
 # app/api/v1/vendor/customers.py
 """
 Vendor customer management endpoints.
+
+Vendor Context: Uses token_vendor_id from JWT token (authenticated vendor API pattern)
 """
 
 import logging
@@ -11,21 +13,27 @@ from sqlalchemy.orm import Session
 
 from app.api.deps import get_current_vendor_api
 from app.core.database import get_db
-from middleware.vendor_context import require_vendor_context
+from app.exceptions import InvalidTokenException
+from app.services.vendor_service import vendor_service
 from models.database.user import User
-from models.database.vendor import Vendor
 
 router = APIRouter(prefix="/customers")
 logger = logging.getLogger(__name__)
 
 
+def _get_vendor_from_token(current_user: User, db: Session):
+    """Helper to get vendor from JWT token."""
+    if not hasattr(current_user, "token_vendor_id"):
+        raise InvalidTokenException("Token missing vendor information. Please login again.")
+    return vendor_service.get_vendor_by_id(db, current_user.token_vendor_id)
+
+
 @router.get("")
 def get_vendor_customers(
     skip: int = Query(0, ge=0),
     limit: int = Query(100, ge=1, le=1000),
     search: str | None = Query(None),
     is_active: bool | None = Query(None),
-    vendor: Vendor = Depends(require_vendor_context()),
     current_user: User = Depends(get_current_vendor_api),
     db: Session = Depends(get_db),
 ):
@@ -38,6 +46,7 @@ def get_vendor_customers(
     - Support filtering by active status
     - Return paginated results
     """
+    vendor = _get_vendor_from_token(current_user, db)  # noqa: F841 - vendor will be used when implemented
     return {
         "customers": [],
         "total": 0,
@@ -50,7 +59,6 @@ def get_vendor_customers(
 @router.get("/{customer_id}")
 def get_customer_details(
     customer_id: int,
-    vendor: Vendor = Depends(require_vendor_context()),
     current_user: User = Depends(get_current_vendor_api),
     db: Session = Depends(get_db),
 ):
@@ -63,13 +71,13 @@ def get_customer_details(
     - Include order history
     - Include total spent, etc.
     """
+    vendor = _get_vendor_from_token(current_user, db)  # noqa: F841 - vendor will be used when implemented
     return {"message": "Customer details coming in Slice 4"}
 
 
 @router.get("/{customer_id}/orders")
 def get_customer_orders(
     customer_id: int,
-    vendor: Vendor = Depends(require_vendor_context()),
     current_user: User = Depends(get_current_vendor_api),
     db: Session = Depends(get_db),
 ):
@@ -81,6 +89,7 @@ def get_customer_orders(
     - Filter by vendor_id
     - Return order details
     """
+    vendor = _get_vendor_from_token(current_user, db)  # noqa: F841 - vendor will be used when implemented
     return {"orders": [], "message": "Customer orders coming in Slice 5"}
 
 
@@ -88,7 +97,6 @@ def get_customer_orders(
 def update_customer(
     customer_id: int,
     customer_data: dict,
-    vendor: Vendor = Depends(require_vendor_context()),
     current_user: User = Depends(get_current_vendor_api),
     db: Session = Depends(get_db),
 ):
@@ -100,13 +108,13 @@ def update_customer(
     - Verify customer belongs to vendor
     - Update customer preferences
     """
+    vendor = _get_vendor_from_token(current_user, db)  # noqa: F841 - vendor will be used when implemented
     return {"message": "Customer update coming in Slice 4"}
 
 
 @router.put("/{customer_id}/status")
 def toggle_customer_status(
     customer_id: int,
-    vendor: Vendor = Depends(require_vendor_context()),
     current_user: User = Depends(get_current_vendor_api),
     db: Session = Depends(get_db),
 ):
@@ -118,13 +126,13 @@ def toggle_customer_status(
     - Verify customer belongs to vendor
     - Log the change
     """
+    vendor = _get_vendor_from_token(current_user, db)  # noqa: F841 - vendor will be used when implemented
     return {"message": "Customer status toggle coming in Slice 4"}
 
 
 @router.get("/{customer_id}/stats")
 def get_customer_statistics(
     customer_id: int,
-    vendor: Vendor = Depends(require_vendor_context()),
     current_user: User = Depends(get_current_vendor_api),
     db: Session = Depends(get_db),
 ):
@@ -137,6 +145,7 @@ def get_customer_statistics(
     - Average order value
     - Last order date
     """
+    vendor = _get_vendor_from_token(current_user, db)  # noqa: F841 - vendor will be used when implemented
     return {
         "total_orders": 0,
         "total_spent": 0.0,