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>

tests/unit/middleware/test_store_context.py

@@ -438,7 +438,7 @@ class TestStoreContextManager:
     def test_extract_store_from_referer_subdomain(self):
         """Test extracting store from referer with subdomain."""
         request = Mock(spec=Request)
-        request.headers = {"referer": "http://orion.platform.com/storefront/products"}
+        request.headers = {"referer": "http://orion.platform.com/storefront/products"}  # noqa: SEC034
 
         with patch("middleware.store_context.settings") as mock_settings:
             mock_settings.platform_domain = "platform.com"
@@ -453,7 +453,7 @@ class TestStoreContextManager:
     def test_extract_store_from_referer_custom_domain(self):
         """Test extracting store from referer with custom domain."""
         request = Mock(spec=Request)
-        request.headers = {"referer": "http://my-custom-shop.com/storefront/products"}
+        request.headers = {"referer": "http://my-custom-shop.com/storefront/products"}  # noqa: SEC034
 
         with patch("middleware.store_context.settings") as mock_settings:
             mock_settings.platform_domain = "platform.com"
@@ -487,7 +487,7 @@ class TestStoreContextManager:
     def test_extract_store_from_referer_ignores_admin_subdomain(self):
         """Test that admin subdomain is not extracted from referer."""
         request = Mock(spec=Request)
-        request.headers = {"referer": "http://admin.platform.com/dashboard"}
+        request.headers = {"referer": "http://admin.platform.com/dashboard"}  # noqa: SEC034
 
         with patch("middleware.store_context.settings") as mock_settings:
             mock_settings.platform_domain = "platform.com"
@@ -500,7 +500,7 @@ class TestStoreContextManager:
     def test_extract_store_from_referer_ignores_www_subdomain(self):
         """Test that www subdomain is not extracted from referer."""
         request = Mock(spec=Request)
-        request.headers = {"referer": "http://www.platform.com/storefront"}
+        request.headers = {"referer": "http://www.platform.com/storefront"}  # noqa: SEC034
 
         with patch("middleware.store_context.settings") as mock_settings:
             mock_settings.platform_domain = "platform.com"