feat: Phase 2-5 API test scripts + create_monitor_job fix

Phase 2: 10/10 passed ✅
Phase 3: 7/7 passed ✅
Phase 4: 9/11 passed (2 known bugs - i.name column)
Phase 5: 13/23 passed (10 failures - pre-existing bugs)

Fixes:
- create_monitor_job: ON CONFLICT (uuid) DO UPDATE to prevent duplicate key errors
- test scripts: Correct request bodies for all visual search endpoints

src/core/db/postgres_db.rs

@@ -1426,7 +1426,7 @@ impl PostgresDb {
                 r#"
                 INSERT INTO {} (uuid, video_path, status, video_id)
                 VALUES ($1, $2, 'pending', $3)
-                ON CONFLICT DO NOTHING
+                ON CONFLICT (uuid) DO UPDATE SET status = 'pending', updated_at = NOW()
                 RETURNING id, uuid, video_path, status, current_processor, progress_total, progress_current, error_count, last_error, started_at::TEXT, updated_at::TEXT, created_at::TEXT, processors, completed_processors, failed_processors, video_id
                 "#,
                 jobs_table