Related: #87299
Related: #89930

What Problem This Solves

Resolves a Telegram late-dispatch boundary where a visible final reply could be followed by a generic error fallback if dispatch cleanup failed afterward.

The branch had also become unmergeable after upstream Telegram dispatch changes. This update rebases the proof harness onto current origin/main, resolves the conflicts, and keeps the fallback suppression tied to final-answer delivery rather than any partial/progress delivery.

Why This Change Was Made

This adds a trusted private-QA proof scenario, --proof-scenario late-dispatch-after-final, and passes it into the local Telegram gateway as OPENCLAW_TELEGRAM_QA_DISPATCH_FAULT=late-dispatch-after-final. The Telegram hook remains gated by OPENCLAW_BUILD_PRIVATE_QA=1, OPENCLAW_ENABLE_PRIVATE_QA_CLI=1, and the exact scenario value.

The proof runner also rejects candidate SUT checkouts that do not contain the matching Telegram QA fault hook, and the Mantis Telegram Desktop prompt tells agents to rebase onto the harness or test a merge result instead of treating an unsupported candidate run as proof. The SUT support guard now checks for the hook in the exported dispatchTelegramMessage dispatch path rather than accepting loose stale strings or fake dispatcher snippets (RF-003). The runtime fallback guard now suppresses duplicate generic fallback only after a final answer has been delivered, while preserving the error fallback after partial-only output failures. Spooled replay completion still treats already visible output as delivered so draft/progress output is not retried unnecessarily.

Maintainers should still decide whether carrying this private-QA runtime hook and trusted proof-runner behavior in bundled Telegram source is acceptable (RF-004, RF-005).

User Impact

Developers and maintainers can now run a deterministic Telegram proof scenario for the late-dispatch-after-final boundary, and proof agents get a clear failure instead of misleading exact-path evidence when a candidate checkout lacks the hook.

Telegram users no longer receive a second generic error reply after a visible final answer is already delivered. If dispatch fails after only partial/block output, the existing terminal error fallback is still sent.

Evidence

Before this update, check-main-drift reported has_conflicts: true and sync-main reproduced conflicts in:

• extensions/telegram/src/bot-message-dispatch.ts
• extensions/telegram/src/bot-message-dispatch.test.ts
• scripts/e2e/telegram-user-crabbox-proof.ts
• test/scripts/telegram-user-crabbox-proof.test.ts

After resolving the conflicts, check-main-drift reports has_conflicts: false against current origin/main; the updated branch is squashed to a single commit on top of origin/main (RF-002). Validation included the rebased full-file suites before the final focused guard hardening:

$ pnpm exec vitest run extensions/telegram/src/bot-message-dispatch.test.ts
Test Files  1 passed (1)
     Tests  147 passed (147)
  Duration  18.83s

$ pnpm exec vitest run test/scripts/telegram-user-crabbox-proof.test.ts
Test Files  1 passed (1)
     Tests  32 passed (32)
  Duration  4.98s

$ pnpm run check:no-conflict-markers
$ node scripts/check-no-conflict-markers.mjs

Additional focused validation on the current head:

$ pnpm exec vitest run test/scripts/telegram-user-crabbox-proof.test.ts -t "fake dispatcher option block|cleans local SUT children"
Test Files  1 passed (1)
     Tests  2 passed | 31 skipped (33)
  Duration  2.10s

$ pnpm exec vitest run extensions/telegram/src/bot-message-dispatch.test.ts -t "does not return retryable after spooled replay already showed visible output|returns retryable when dispatch fails after partial output and the fallback is not delivered|returns retryable when spooled replay suppresses fallback after non-silent delivery skip"
Test Files  1 passed (1)
     Tests  3 passed | 145 skipped (148)
  Duration  17.68s

$ git diff --check

Current limitations: this PR still does not include a fresh live Telegram Desktop forced late-dispatch capture (RF-001). The intended exact-path consumer remains the downstream Telegram behavior-fix proof after this harness lands or is tested as a merge result.