Submit a screenshot observation

DEVICE TOKEN ONLY. Upload one monotonically sequenced, one-frame PNG/JPEG. The encoded payload is limited to 10,485,760 base64 characters (after an optional exact PNG/JPEG data-URI prefix), and decoded dimensions to 320x240 through 3840x2160. The server verifies format, dimensions, and the optional submitted-byte SHA-256, then strips metadata and re-encodes; the response SHA-256 covers those normalized bytes and may differ. Identical sequence replays are safe; reusing a sequence with different bytes is 409. Live transport frames are encrypted, logically expire after 15 minutes, and are excluded from SSE, webhooks, ordinary logs, and ordinary durable run history. Separately, if a live BYOK Task, Workflow, or schedule uses a frame for a visual decision, the fail-closed pre-provider audit retains an exact model-input copy under the account-lifetime screenshot rules.