Queue test runs for all test cases on a specific app file

Queue test runs for ALL test cases in your organization on a specific application file.

**Process:**
1. Validates that the requested device exists in the devices table with availability=True
2. Validates that app_file_id belongs to your organization
3. Fetches all active test cases for your organization (optionally filtered by category)
4. Creates test_run records for each test case with 'queued' status
5. Creates job records for the test execution queue

**Category Filtering:**
- Optional: Provide category_id to run only test cases in a specific category
- If category_id is provided, only test cases in that category will be queued
- If no category_id is provided, all active test cases will be queued

**Returns:**
- Links to view each test run at https://app.qualgent.ai/test-runs/{id}
- Returns count of total test runs created

**Transaction Handling:**
- If any job fails, all jobs in the batch are rolled back
- Ensures data consistency across test_runs and test_jobs_pgqueuer tables

**Note:**
- If there are no test cases (or no test cases in the specified category), returns empty jobs array
- Only active test cases are included