API Platform: Updated API response header names

If your client reads QuiverAI's data posture response headers, switch their prefix from x-quiver- to x-quiverai-. This affects inference-data-policy, payload-capture, request-metadata-policy and request-metadata-retention-seconds. Sandbox responses use x-quiverai-environment: test.

The old names continue to carry identical values until December 31, 2026, when they're scheduled for removal.

The x-quiver-zero-data-retention header has already been removed. QuiverAI says it never represented a ratified zero-data-retention guarantee. The underlying data policies and retention behavior haven't changed.