fix: remove unused ShopVerificationException (NAM-004)

Remove legacy ShopVerificationException class that was never used.
VendorVerificationException already exists and serves the same purpose.

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

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

app/exceptions/admin.py

@@ -58,30 +58,6 @@ class UserStatusChangeException(BusinessLogicException):
         )
 
 
-class ShopVerificationException(BusinessLogicException):
-    """Raised when shop verification fails."""
-
-    def __init__(
-        self,
-        shop_id: int,
-        reason: str,
-        current_verification_status: bool | None = None,
-    ):
-        details = {
-            "shop_id": shop_id,
-            "reason": reason,
-        }
-
-        if current_verification_status is not None:
-            details["current_verification_status"] = current_verification_status
-
-        super().__init__(
-            message=f"Shop verification failed for shop {shop_id}: {reason}",
-            error_code="SHOP_VERIFICATION_FAILED",
-            details=details,
-        )
-
-
 class AdminOperationException(BusinessLogicException):
     """Raised when admin operation fails."""