A provider handoff drops the thread's active goal; the new provider's get_goal returns null #30429

What happened. A thread on OpenCode had an active, unfinished goal. After T3 handed the thread to Codex, get_goal on the new Codex session returned null, although the resume record named the active goal on the old session. The coordinator recreated the goal by hand. That left two goal controllers, and the user could not tell which goal was live.

Expected. A provider handoff either carries the goal across or names its owner explicitly (old session, goal state, accounting). It should never orphan the goal silently or let a second controller appear without anyone noticing.

Cause, from a local patch we did not ship. Handoff records do not keep the native goal owner or the goal's state. Keeping the owner, goal state, accounting and the source timestamp in the handoff record fixes it, including across a second switch and a failed native resume. Deliver that record outside trimmable history, and say plainly that it grants no authority to create another controller. A regression test for owner preservation failed before the change and passed after it.

Environment. macOS (Apple silicon), T3 Code with Codex and OpenCode providers, 2 Nov 2026.