refactor: enforce strict architecture rules and add Pydantic response models

- Update architecture rules to be stricter (API-003 now blocks ALL exception
  raising in endpoints, not just HTTPException)
- Update get_current_vendor_api dependency to guarantee token_vendor_id presence
- Remove redundant _get_vendor_from_token helpers from all vendor API files
- Move vendor access validation to service layer methods
- Add Pydantic response models for media, notification, and payment endpoints
- Add get_active_vendor_by_code service method for public vendor lookup
- Add get_import_job_for_vendor service method with vendor validation
- Update validation script to detect exception raising patterns in endpoints

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

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

app/api/v1/vendor/info.py

@@ -10,48 +10,16 @@ This module provides:
 import logging
 
 from fastapi import APIRouter, Depends, Path
-from sqlalchemy import func
 from sqlalchemy.orm import Session
 
 from app.core.database import get_db
-from app.exceptions import VendorNotFoundException
-from models.database.vendor import Vendor
+from app.services.vendor_service import vendor_service
 from models.schema.vendor import VendorDetailResponse
 
 router = APIRouter()
 logger = logging.getLogger(__name__)
 
 
-def _get_vendor_by_code(db: Session, vendor_code: str) -> Vendor:
-    """
-    Helper to get active vendor by vendor_code.
-
-    Args:
-        db: Database session
-        vendor_code: Vendor code (case-insensitive)
-
-    Returns:
-        Vendor object
-
-    Raises:
-        VendorNotFoundException: If vendor not found or inactive
-    """
-    vendor = (
-        db.query(Vendor)
-        .filter(
-            func.upper(Vendor.vendor_code) == vendor_code.upper(),
-            Vendor.is_active == True,
-        )
-        .first()
-    )
-
-    if not vendor:
-        logger.warning(f"Vendor not found or inactive: {vendor_code}")
-        raise VendorNotFoundException(vendor_code, identifier_type="code")
-
-    return vendor
-
-
 @router.get("/{vendor_code}", response_model=VendorDetailResponse)
 def get_vendor_info(
     vendor_code: str = Path(..., description="Vendor code"),
@@ -81,7 +49,7 @@ def get_vendor_info(
     """
     logger.info(f"Public vendor info request: {vendor_code}")
 
-    vendor = _get_vendor_by_code(db, vendor_code)
+    vendor = vendor_service.get_active_vendor_by_code(db, vendor_code)
 
     logger.info(f"Vendor info retrieved: {vendor.name} ({vendor.vendor_code})")