fix: correct tojson|safe usage in templates and update validator

- Remove |safe from |tojson in HTML attributes (x-data) - quotes must
  become " for browsers to parse correctly
- Update LANG-002 and LANG-003 architecture rules to document correct
  |tojson usage patterns:
  - HTML attributes: |tojson (no |safe)
  - Script blocks: |tojson|safe
- Fix validator to warn when |tojson|safe is used in x-data (breaks
  HTML attribute parsing)
- Improve code quality across services, APIs, and tests

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

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

tests/unit/models/database/test_order.py

@@ -1,5 +1,6 @@
 # tests/unit/models/database/test_order.py
 """Unit tests for Order and OrderItem database models."""
+
 import pytest
 from sqlalchemy.exc import IntegrityError
 
@@ -74,7 +75,14 @@ class TestOrderModel:
         self, db, test_vendor, test_customer, test_customer_address
     ):
         """Test Order with different status values."""
-        statuses = ["pending", "confirmed", "processing", "shipped", "delivered", "cancelled"]
+        statuses = [
+            "pending",
+            "confirmed",
+            "processing",
+            "shipped",
+            "delivered",
+            "cancelled",
+        ]
 
         for i, status in enumerate(statuses):
             order = Order(
@@ -93,9 +101,7 @@ class TestOrderModel:
 
             assert order.status == status
 
-    def test_order_amounts(
-        self, db, test_vendor, test_customer, test_customer_address
-    ):
+    def test_order_amounts(self, db, test_vendor, test_customer, test_customer_address):
         """Test Order amount fields."""
         order = Order(
             vendor_id=test_vendor.id,