feat(validators): add noqa suppression support to security and performance validators

- Add centralized _is_noqa_suppressed() to BaseValidator with normalization
  (accepts both SEC001 and SEC-001 formats for ruff compatibility)
- Wire noqa support into all 21 security and 18 performance check functions
- Add ruff external config for SEC/PERF/MOD/EXC codes in pyproject.toml
- Convert all 280 Python noqa comments to dashless format (ruff-compatible)
- Add site/ to IGNORE_PATTERNS (excludes mkdocs build output)
- Suppress 152 false positive findings (test passwords, seed data, validator
  self-references, Apple Wallet SHA1, etc.)
- Security: 79 errors → 0, 60 warnings → 0
- Performance: 80 warnings → 77 (3 test script suppressions)
- Add proposal doc with noqa inventory and remaining findings recommendations

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

app/modules/cart/exceptions.py

@@ -37,7 +37,7 @@ class CartItemNotFoundException(ResourceNotFoundException):
         self.details.update({"product_id": product_id, "session_id": session_id})
 
 
-class EmptyCartException(ValidationException):  # noqa: MOD-025
+class EmptyCartException(ValidationException):  # noqa: MOD025
     """Raised when trying to perform operations on an empty cart."""
 
     def __init__(self, session_id: str):
@@ -45,7 +45,7 @@ class EmptyCartException(ValidationException):  # noqa: MOD-025
         self.error_code = "CART_EMPTY"
 
 
-class CartValidationException(ValidationException):  # noqa: MOD-025
+class CartValidationException(ValidationException):  # noqa: MOD025
     """Raised when cart data validation fails."""
 
     def __init__(
@@ -113,7 +113,7 @@ class InvalidCartQuantityException(ValidationException):
         self.error_code = "INVALID_CART_QUANTITY"
 
 
-class ProductNotAvailableForCartException(BusinessLogicException):  # noqa: MOD-025
+class ProductNotAvailableForCartException(BusinessLogicException):  # noqa: MOD025
     """Raised when product is not available for adding to cart."""
 
     def __init__(self, product_id: int, reason: str):