fix(orchestrator): timestamp-based comment-walk for input-required (#35)

[nitzanvolman]

Summary

Fixes #35.

recoverInputRequired and checkTrackerReplies (internal/orchestrator/event_loop.go) walked detailed.Comments by array position, implicitly assuming chronological order. Linear's GraphQL comments(first: 50, orderBy: createdAt) (internal/tracker/linear/queries.go:53) returns comments newest-first by default. On Linear, the reverse-index walk finds the oldest 🤖 comment, then the forward walk traverses older comments — so any non-🤖 comment in the issue's history is misread as a fresh user reply. checkTrackerReplies deletes the state.InputRequiredIssues entry and dispatches a "resumed" worker; recoverInputRequired returns nil for the same reason. Both safety paths fail simultaneously, producing the 49-loop documented in the issue.

Fix

Replace the two index-walks with helpers that compare domain.Comment.CreatedAt timestamps:

• findLatestItervoxComment — scans the full slice, returns the index/CreatedAt of the most recently created 🤖-prefixed comment. No ordering assumption.
• firstReplyAfter(comments, t) — returns the body of the first non-🤖 comment with CreatedAt > t. Conservatively skips comments with nil CreatedAt.

recoverInputRequired and checkTrackerReplies are rewritten to use these helpers. Behaviour is correct on Linear (descending), GitHub (ascending), and any other ordering.

Test plan

• New whitebox test file internal/orchestrator/event_loop_internal_test.go (9 cases): descending-order Linear-style with no reply, descending with reply, ascending with no reply, ascending with reply, no comments, nil CreatedAt, and checkTrackerReplies regression cases for both orderings.
• The two descending-order regression tests fail against main's event_loop.go and pass under this fix.
• go test -race ./internal/orchestrator/... — green
• go test -race -count=5 ./internal/orchestrator/... — green (no flakes)
• make verify — exit 0 (fmt, vet, golangci-lint, full Go race tests, web 45 files / 409 tests, spelling guard)

Out of scope (follow-ups, not in this PR)

• Async fire-and-forget 🤖 posting (event_loop.go:967-973) has no retry; if the tracker rejects the comment, recovery still loses its anchor.
• Codex worker break ordering (worker.go:452 runs before :461) can drop the input-required signal entirely for Codex when the sentinel isn't in the last 3 text blocks of the final agent message.
• Distinguishing agent-posted vs human-posted comments (e.g. via author identity or a hidden marker) for defense-in-depth.

🤖 Generated with Claude Code