Correction Studio API

• GET /api/datasets — available dataset/method baselines
• GET /api/meta?dataset=&method=&max_n= — per-dataset metadata
• GET /api/points?dataset=&method=&ids=&max_n= — raw feature vectors for the point inspector
• GET /api/run?dataset=&method=&g=&r=&n_landmarks=&lr=&alpha=&k=&max_n=&remove= — SSE stream of frames