refactor: convert legacy services/tasks to re-exports

Legacy service and task files now re-export from module locations:

app/services/:
- stats_service.py -> app.modules.analytics.services
- usage_service.py -> app.modules.analytics.services

app/tasks/celery_tasks/:
- code_quality.py -> app.modules.dev_tools.tasks
- test_runner.py -> app.modules.dev_tools.tasks

Maintains backwards compatibility while actual code lives
in self-contained modules.

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

app/tasks/celery_tasks/test_runner.py

@@ -1,83 +1,15 @@
 # app/tasks/celery_tasks/test_runner.py
 """
-Celery tasks for test execution.
+Celery tasks for test execution - LEGACY LOCATION
 
-Wraps the existing execute_test_run function for Celery execution.
+This file exists for backward compatibility.
+The canonical location is now: app/modules/dev_tools/tasks/test_runner.py
+
+All imports should use the new location:
+    from app.modules.dev_tools.tasks import execute_test_run
 """
 
-import logging
+# Re-export from canonical location for backward compatibility
+from app.modules.dev_tools.tasks.test_runner import execute_test_run
 
-from app.core.celery_config import celery_app
-from app.services.test_runner_service import test_runner_service
-from app.tasks.celery_tasks.base import DatabaseTask
-from models.database.test_run import TestRun
-
-logger = logging.getLogger(__name__)
-
-
-@celery_app.task(
-    bind=True,
-    base=DatabaseTask,
-    name="app.tasks.celery_tasks.test_runner.execute_test_run",
-    max_retries=1,
-    time_limit=3600,  # 1 hour hard limit
-    soft_time_limit=3300,  # 55 minutes soft limit
-)
-def execute_test_run(
-    self,
-    run_id: int,
-    test_path: str = "tests",
-    extra_args: list[str] | None = None,
-):
-    """
-    Celery task to execute pytest tests.
-
-    Args:
-        run_id: ID of the TestRun record
-        test_path: Path to tests (relative to project root)
-        extra_args: Additional pytest arguments
-
-    Returns:
-        dict: Test run results summary
-    """
-    with self.get_db() as db:
-        # Get the test run record
-        test_run = db.query(TestRun).filter(TestRun.id == run_id).first()
-        if not test_run:
-            logger.error(f"Test run {run_id} not found")
-            return {"error": f"Test run {run_id} not found"}
-
-        # Store Celery task ID
-        test_run.celery_task_id = self.request.id
-        db.commit()
-
-        try:
-            logger.info(f"Starting test execution: Run {run_id}, Path: {test_path}")
-
-            # Execute the tests
-            test_runner_service._execute_tests(db, test_run, test_path, extra_args)
-            db.commit()
-
-            logger.info(
-                f"Test run {run_id} completed: "
-                f"status={test_run.status}, passed={test_run.passed}, "
-                f"failed={test_run.failed}, duration={test_run.duration_seconds:.1f}s"
-            )
-
-            return {
-                "run_id": run_id,
-                "status": test_run.status,
-                "total_tests": test_run.total_tests,
-                "passed": test_run.passed,
-                "failed": test_run.failed,
-                "errors": test_run.errors,
-                "skipped": test_run.skipped,
-                "coverage_percent": test_run.coverage_percent,
-                "duration_seconds": test_run.duration_seconds,
-            }
-
-        except Exception as e:
-            logger.error(f"Test run {run_id} failed: {e}", exc_info=True)
-            test_run.status = "error"
-            db.commit()
-            raise  # Re-raise for Celery
+__all__ = ["execute_test_run"]