feat: complete dev_tools module self-containment

Migrate dev_tools module to self-contained structure:

- routes/api/ - API endpoints
- models/architecture_scan.py - Architecture scan models
- models/test_run.py - Test run models
- schemas/ - Pydantic schemas
- services/ - Business logic services
- tasks/ - Celery background tasks
- exceptions.py - Module exceptions

Updated definition.py with self-contained paths.

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

app/modules/dev_tools/routes/__init__.py

@@ -2,14 +2,15 @@
 """
 Dev-Tools module route registration.
 
-This module provides functions to register dev-tools routes
-with module-based access control.
+This module provides dev-tools routes with module-based access control.
 
-Note: Dev-Tools module has primarily page routes, not API routes.
-The page routes are defined in admin/vendor page handlers.
+Structure:
+- routes/api/ - REST API endpoints (code quality, tests)
+- routes/pages/ - HTML page rendering (component library, icons)
+
+Note: Dev-tools is an internal module (admin-only), so there is no vendor router.
 """
 
-# Dev-tools has minimal API routes - primarily page routes
-# No auto-imports needed
+from app.modules.dev_tools.routes.api import admin_router
 
-__all__ = []
+__all__ = ["admin_router"]