Replaces the hello-name template with a tracker that assigns a UUID4
run_id to every prediction and appends (timestamp, model_version,
input_hash, output, latency_ms) to runs.jsonl. Two stub predictors ship
so the Space runs with no weights to download; swap in a real model by
editing predictors.predict().
Tabs: Predict (text/image, model dropdown), History (filter + detail),
Stats (per-model p50/p95 + runs-per-day), Download (file + guarded
clear). Thread-safe writes via threading.Lock; 8 unit tests cover
hashing, filters, clear, and 100-worker concurrent appends.
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
