Fixescoder/internal#1519
Fixes CODAGT-353
These nine tests were skipped pending a chatd notification flow refactor
that would let workers distinguish stale control `NOTIFY` messages from
real interrupts. They now pass consistently, so this drops the `t.Skip`
calls and the now-stale `TODO(CODAGT-353)` blocks.
While rerunning the package after unskipping them,
`TestNewReplicaRecoversStaleChatFromDeadReplica` also surfaced as flaky
on `main` because it asserted transient ownership state. This PR keeps
that server-level test as a stable end-to-end recovery check and adds a
deterministic worker-level stale reacquisition test so we still directly
cover lease takeover behavior.
## Tests unskipped
- `coderd`: `TestPatchChatMessage/ChangesModel`
- `coderd/x/chatd`:
- `TestExploreChatSendMessageCannotMutateMCPSnapshot`
- `TestAutoPromoteQueuedMessagesPreservesPerTurnModelOrder`
- `TestSignalWakeSendMessage`
- `TestAdvisorChainMode_SnapshotKeepsFullHistory`
- `TestOpenAIResponsesNoStaleWebSearchReplay`
- `TestOpenAIResponsesFullReplayPairsReasoningAndWebSearch`
- `TestOpenAIResponsesChainModeSkipsWhenLocalCallPending`
- `TestOpenAIResponsesChainModeStillFiresForProviderExecutedOnly`
## Stale recovery follow-up
- `coderd/x/chatd`: `TestNewReplicaRecoversStaleChatFromDeadReplica` now
waits for the stable `waiting` and unowned end state after recovery.
- `coderd/x/chatd`: `TestWorker_ReacquiresStaleOwnedChat` blocks the
runner after reacquisition and directly asserts the new worker
ownership, new runner ID, and fresh heartbeat.
I stress-ran the stale recovery tests locally with repeated plain and
race runs, and re-ran the nine unskipped tests plus
`TestPatchChatMessage/ChangesModel` after these follow-up changes.
Hugo Dutka