feat: implement code quality dashboard with architecture violation tracking

Implement comprehensive code quality dashboard (Phase 2-4) to track and manage
architecture violations found by the validation script.

Backend Implementation:
- Add JSON output support to validate_architecture.py script
- Create CodeQualityService with scan management, violation tracking, and statistics
- Implement REST API endpoints for code quality management:
  * POST /admin/code-quality/scan - trigger new architecture scan
  * GET /admin/code-quality/scans - list scan history
  * GET /admin/code-quality/violations - list violations with filtering/pagination
  * GET /admin/code-quality/violations/{id} - get violation details
  * POST /admin/code-quality/violations/{id}/assign - assign to developer
  * POST /admin/code-quality/violations/{id}/resolve - mark as resolved
  * POST /admin/code-quality/violations/{id}/ignore - mark as ignored
  * POST /admin/code-quality/violations/{id}/comments - add comments
  * GET /admin/code-quality/stats - dashboard statistics
- Fix architecture_scan model imports to use app.core.database

Frontend Implementation:
- Create code quality dashboard page (code-quality-dashboard.html)
  * Summary cards for total violations, errors, warnings, health score
  * Status breakdown (open, assigned, resolved, ignored)
  * Trend visualization for last 7 scans
  * Top violating files list
  * Violations by rule and module
  * Quick action links
- Create violations list page (code-quality-violations.html)
  * Filterable table by severity, status, rule ID, file path
  * Pagination support
  * Violation detail view links
- Add Alpine.js components (code-quality-dashboard.js, code-quality-violations.js)
  * Dashboard state management and scan triggering
  * Violations list with filtering and pagination
  * API integration with authentication
- Add "Code Quality" navigation link in admin sidebar (Developer Tools section)

Routes:
- GET /admin/code-quality - dashboard page
- GET /admin/code-quality/violations - violations list
- GET /admin/code-quality/violations/{id} - violation details

Features:
- Real-time scan execution from UI
- Technical debt score calculation (0-100 scale)
- Violation workflow: open → assigned → resolved/ignored
- Trend tracking across multiple scans
- File and module-level insights
- Assignment system with priorities and due dates
- Collaborative comments on violations

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

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

app/routes/admin_pages.py

@@ -25,6 +25,9 @@ Routes:
 - GET /content-pages → Content pages list (auth required)
 - GET /content-pages/create → Create content page (auth required)
 - GET /content-pages/{page_id}/edit → Edit content page (auth required)
+- GET /code-quality → Code quality dashboard (auth required)
+- GET /code-quality/violations → Violations list (auth required)
+- GET /code-quality/violations/{violation_id} → Violation details (auth required)
 """
 
 from fastapi import APIRouter, Request, Depends, Path
@@ -490,3 +493,66 @@ async def admin_test_vendors_users_migration(
             "user": current_user,
         }
     )
+
+
+# ============================================================================
+# CODE QUALITY & ARCHITECTURE ROUTES
+# ============================================================================
+
+@router.get("/code-quality", response_class=HTMLResponse, include_in_schema=False)
+async def admin_code_quality_dashboard(
+        request: Request,
+        current_user: User = Depends(get_current_admin_from_cookie_or_header),
+        db: Session = Depends(get_db)
+):
+    """
+    Render code quality dashboard.
+    Shows architecture violations, trends, and technical debt score.
+    """
+    return templates.TemplateResponse(
+        "admin/code-quality-dashboard.html",
+        {
+            "request": request,
+            "user": current_user,
+        }
+    )
+
+
+@router.get("/code-quality/violations", response_class=HTMLResponse, include_in_schema=False)
+async def admin_code_quality_violations(
+        request: Request,
+        current_user: User = Depends(get_current_admin_from_cookie_or_header),
+        db: Session = Depends(get_db)
+):
+    """
+    Render violations list page.
+    Shows all violations with filtering and sorting options.
+    """
+    return templates.TemplateResponse(
+        "admin/code-quality-violations.html",
+        {
+            "request": request,
+            "user": current_user,
+        }
+    )
+
+
+@router.get("/code-quality/violations/{violation_id}", response_class=HTMLResponse, include_in_schema=False)
+async def admin_code_quality_violation_detail(
+        request: Request,
+        violation_id: int = Path(..., description="Violation ID"),
+        current_user: User = Depends(get_current_admin_from_cookie_or_header),
+        db: Session = Depends(get_db)
+):
+    """
+    Render violation detail page.
+    Shows violation details, code context, assignments, and comments.
+    """
+    return templates.TemplateResponse(
+        "admin/code-quality-violation-detail.html",
+        {
+            "request": request,
+            "user": current_user,
+            "violation_id": violation_id,
+        }
+    )