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/models/__init__.py

@@ -0,0 +1,45 @@
+# app/modules/dev_tools/models/__init__.py
+"""
+Dev-Tools module database models.
+
+This is the canonical location for dev-tools models. Module models are automatically
+discovered and registered with SQLAlchemy's Base.metadata at startup.
+
+Usage:
+    from app.modules.dev_tools.models import (
+        ArchitectureScan,
+        ArchitectureViolation,
+        ArchitectureRule,
+        ViolationAssignment,
+        ViolationComment,
+        TestRun,
+        TestResult,
+        TestCollection,
+    )
+"""
+
+from app.modules.dev_tools.models.architecture_scan import (
+    ArchitectureScan,
+    ArchitectureViolation,
+    ArchitectureRule,
+    ViolationAssignment,
+    ViolationComment,
+)
+from app.modules.dev_tools.models.test_run import (
+    TestRun,
+    TestResult,
+    TestCollection,
+)
+
+__all__ = [
+    # Architecture scan models
+    "ArchitectureScan",
+    "ArchitectureViolation",
+    "ArchitectureRule",
+    "ViolationAssignment",
+    "ViolationComment",
+    # Test run models
+    "TestRun",
+    "TestResult",
+    "TestCollection",
+]