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>

scripts/validate_architecture.py

@@ -584,6 +584,36 @@ class ArchitectureValidator:
             print("=" * 80)
             return 0
 
+    def print_json(self) -> int:
+        """Print validation results as JSON"""
+        import json
+
+        violations_json = []
+        for v in self.result.violations:
+            rel_path = str(v.file_path.relative_to(self.project_root)) if self.project_root in v.file_path.parents else str(v.file_path)
+            violations_json.append({
+                'rule_id': v.rule_id,
+                'rule_name': v.rule_name,
+                'severity': v.severity.value,
+                'file_path': rel_path,
+                'line_number': v.line_number,
+                'message': v.message,
+                'context': v.context or '',
+                'suggestion': v.suggestion or ''
+            })
+
+        output = {
+            'files_checked': self.result.files_checked,
+            'total_violations': len(self.result.violations),
+            'errors': len([v for v in self.result.violations if v.severity == Severity.ERROR]),
+            'warnings': len([v for v in self.result.violations if v.severity == Severity.WARNING]),
+            'violations': violations_json
+        }
+
+        print(json.dumps(output, indent=2))
+
+        return 1 if self.result.has_errors() else 0
+
     def _print_violation(self, v: Violation):
         """Print a single violation"""
         rel_path = v.file_path.relative_to(self.project_root) if self.project_root in v.file_path.parents else v.file_path
@@ -634,6 +664,12 @@ def main():
         help="Only show errors, suppress warnings"
     )
 
+    parser.add_argument(
+        '--json',
+        action='store_true',
+        help="Output results as JSON (for programmatic use)"
+    )
+
     args = parser.parse_args()
 
     # Create validator
@@ -642,8 +678,11 @@ def main():
     # Run validation
     result = validator.validate_all(args.path)
 
-    # Print report
-    exit_code = validator.print_report()
+    # Output results
+    if args.json:
+        exit_code = validator.print_json()
+    else:
+        exit_code = validator.print_report()
 
     sys.exit(exit_code)