fix: suppress NO_REPLY at end of message (closes #111)

[fitz123]

Closes #111.

Summary

• Pipeline-style cron prompts (workspace-health, memory-consolidation, backup-git) reliably produce <recap>\n\nNO_REPLY and the recap was being delivered as a real message
• Extends suppression to also accept NO_REPLY alone on the last non-empty line of the trimmed output (in addition to the existing start-of-message rule from fix: NO_REPLY check should use trim/startsWith instead of exact match #80)
• Extracts the suppression check into bot/src/no-reply.ts so stream-relay.ts and cron-runner.ts agree on exactly which patterns suppress
• Same-line patterns (Done. NO_REPLY) and substring prefixes (NO_REPLY_EXTRA) are intentionally NOT matched

Evidence

9 leaked messages across 4 distinct crons in a 2-day window, all the same <summary>\n\nNO_REPLY shape — full samples in #111. Two prompt-side mitigations (per-cron strengthening + platform rule strengthening in #110) failed to change agent behavior; the model's RLHF "report what you did" instinct overrides explicit instructions to emit a bare token.

Test plan

• Unit tests in bot/src/__tests__/stream-relay.test.ts cover end-of-message NO_REPLY (alone on last line, with whitespace, multi-line content above, single-newline, trailing-newline) and reproduce one of the verbatim leaked samples
• Unit tests in bot/src/__tests__/cron-runner.test.ts cover the same pattern set for the cron path
• Same-line Done. NO_REPLY and NO_REPLY_EXTRA substring prefix are NOT suppressed (negative cases pinned)
• All existing NO_REPLY tests still pass (issue fix: NO_REPLY check should use trim/startsWith instead of exact match #80 backward compatibility preserved)
• npx tsc --noEmit clean
• npm test: 1016/1017 pass (1 pre-existing env-specific voice.ts failure unrelated to this change)
• Manual verification: trigger a workspace-health cron after merge — verify suppression

[Copilot]

Pull request overview

Fixes a delivery suppression gap where cron/pipeline prompts often emit summaries ending with NO_REPLY, causing the summary to be delivered instead of suppressed (closes #111). The PR centralizes the suppression logic so both interactive streaming and cron delivery paths apply identical matching rules.

Changes:

• Extend NO_REPLY suppression to also match when NO_REPLY appears alone on the last non-empty line (while preserving the existing start-of-message suppression behavior from #80).
• Extract shared suppression logic into bot/src/no-reply.ts and reuse it from both stream-relay.ts and cron-runner.ts.
• Add unit tests covering end-of-message suppression and negative cases (same-line ... NO_REPLY and NO_REPLY_EXTRA).

Reviewed changes

Copilot reviewed 6 out of 6 changed files in this pull request and generated no comments.

Show a summary per file

File	Description
docs/plans/completed/2026-04-27-issue-111-no-reply-end-of-message.md	Adds a completed plan/write-up documenting the issue, rationale, and test expectations for the suppression change.
bot/src/no-reply.ts	Introduces shouldSuppressNoReply() implementing the shared start-of-message or last-line-only suppression rules.
bot/src/stream-relay.ts	Replaces inline regex suppression with the shared shouldSuppressNoReply() check for interactive streaming delivery.
bot/src/cron-runner.ts	Replaces inline regex suppression with the shared shouldSuppressNoReply() check for LLM cron output delivery.
bot/src/tests/stream-relay.test.ts	Adds test coverage for end-of-message NO_REPLY suppression and explicitly pinned negative cases.
bot/src/tests/cron-runner.test.ts	Adds unit tests for shouldSuppressNoReply() to ensure cron-path behavior matches the same suppression patterns.

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