Continue on non-fatal reactor errors and skip empty checkpoints

[TheGreatAxios]

Summary

• Non-fatal reactor.error (fatal: false) keeps the turn running: turnStateFromEvent does not set status: "failed", the run sink does not sticky-fail, and the TUI paints the error without idling.
• Empty managed cycle checkpoints skip the git commit instead of creating a new empty commit or staging session junk such as partial.jsonl.

Verification

• bun run lint passes (exit 0)
• bun run typecheck passes (exit 0)
• bun run build passes (exit 0)
• Targeted tests for non-fatal reactor errors and empty checkpoint skip pass (exit 0)
• bun run check exits 1 on four tests that also fail on origin/main (torn-base heal write, compact-commit hook, two assembleChatAgent mocks)

Fixes CL-7641

[linear-code]

CL-7641

[TheGreatAxios]

Review · Comment

Non-fatal reactor.error continues the run and empty checkpoints skip; the TUI mapper still clears hadTextDelta on that path.

Findings

• src/tui/stream-event-map.ts:578 — continue branch still sets hadTextDelta = false, then returns an error event. After streamed text deltas, a later connector.reply can paint a second full assistant row. Preserve hadTextDelta on the non-fatal path.

Notes

• Fail-closed fatal: false gate is correct. Empty-checkpoint skip is load-bearing because isomorphic-git still mints a new oid on an unchanged tree.

[TheGreatAxios]

Critic · Comment

isReactorErrorFatal is fail-closed; unique commit matches the title.

Findings

• src/tui/stream-event-map.ts:578 — non-fatal mapper clears hadTextDelta. Sequence: text deltas → { fatal: false } after checkpoint → connector.reply treated as unpainted. Tests only assert “error without idle.”

Notes

• stagedRewrite → liveTurnRefs copies the success path; skip test with junk partial.jsonl does not prove hash equality.