DL-087
Resume is file-materialized + SDK-native: on StartAgentSession{resume_session_id} (authz-gated, no storage locator on any message) the Server reconstructs the post-supersession session-JSONL body from its transcript store (latest checkpoint body verbatim + later delta lines) and hands it to the Runner on a TOP-LEVEL internal SessionsResponse sibling field (outside the command oneof, NOT inside the verbatim public start request); the Runner writes it into the new container’s session dir at PROVISION time via the provision-exec family, before the agent is exec’d; the agent loads it through the SDK’s own setSessionFile/loadEntriesFromFile seam. No control-lane replay, no TranscriptReplay payload, no replay barrier or admission bound, and no RIG-1310 dependency — the co-ratification is retracted (peer-contract relief). Inline-image blobs are out of MVP scope (RIG-1582).
Status: Active (Matt, 2026-07-31)