[test] flock branch in che-telegram-all-mcp-wrapper.sh lock-refused not covered by test-wrapper-mcp-error.sh

[kiki830621]

Problem

test-wrapper-mcp-error.sh (make_fake_wrapper line 79-80) explicitly "forces mkdir mode (skip flock branch) so tests are deterministic". Result:

• flock branch's call site emit_mcp_error_response 0 (wrapper.sh:146) never executed by smoke test
• Linux users hit flock as primary code path
• Caller-site bugs in flock branch unprotected

Surfaced by Codex (P3 #4), Devil's Advocate (Challenge #2 MATERIAL-on-Linux), Logic Reviewer (Finding 3 LOW).

Expected

Option (a) cheapest: 5th test invokes emit_mcp_error_response 0 directly,validates lockHolderPid == null.
Option (b) cleanest: refactor helper into bin/lib/mcp-error.sh + source from both.

Priority

P3 — not blocking PR-1.

Source: surfaced during /idd-verify che-msg#31 (sister bug from verify ensemble — Codex + Devil's Advocate flagged convergently)

Verify report: #90 (comment)
Related issue: PsychQuant/che-msg#31
Related PR: psychquant-claude-plugins#90 (PR-1 ships v1.3.2)

🤖 Filed by /idd-verify Step 5b follow-up triage.