feat(mcp): expose existing queued message commands

[juliusmarminge]

Part 5/16 of the shared-core and MCP stack. Based on #10554. Next: #10556.

Expose queued message list/read/edit/cancel/reorder/promote through ThreadManagementService and the existing queue commands.

Output text is bounded by Unicode code points. Paging is a live offset. Queue ordering, dispatch and replay semantics remain in the existing services.

MCP-only rebuild of #8699, preserving attribution to Julius Marminge's original work. Original branches remain available for separate service follow-ups.

Validation: The composed stack passes 94 tests across 12 focused files, including shared core MCP and real MCP/V2 integration, attachment intake, project RPC/service contracts, and client model command selection. Server/contracts/shared/client-runtime typechecks and targeted format/lint/diff checks pass. New behavior coverage lives with the shared operation; no per-tool mock suite was added. Current-head CI is shown below.

Layer size: 6 files, +191/-6. No domain-service production implementation or documentation files change in this MCP layer.

Prepared with Codex in the OpenAI agent runtime.

Note

Expose six queued-message MCP tools in ThreadToolkit

• Adds t3_queue_list, t3_queue_read, t3_queue_edit, t3_queue_cancel, t3_queue_reorder, and t3_queue_promote_to_steer MCP tools for managing queued thread runs
• List entries cap message text at 1,000 characters; direct reads cap at 16,000 characters, both using Unicode-code-point counting via Array.from
• Mutation handlers dispatch existing orchestration commands through a shared dispatch helper that maps failures to the unavailable MCP error
• Registers t3_queue_list and t3_queue_read in CLAUDE_READ_ONLY_T3_MCP_ALLOWED_TOOLS and adds display names in the shared presentation registry
• Risk: queueEntry helper in handlers.ts returns undefined for non-queued or unmatched runs, causing t3_queue_read to return invalid_request — callers passing a run ID that is not currently queued will see this failure

^{Macroscope summarized 0a74c93.}

[macroscopeapp]

Approvability

Verdict: Not approved

Macroscope's review found this PR not approvable — This PR adds six production MCP queue tools, including destructive mutations, and expands Claude's default read-only tool allowlist. The integration coverage is useful but does not fully exercise the new handler command and failure paths.

No code changes detected at 0a74c93. Prior analysis still applies.

^{You can add or adjust custom eligibility rules. Learn more.}

[github-actions]

Thread transfer impact

⚠️ The latest CI run did not produce a thread transfer result for 0a74c93.

This comment will update automatically after the next completed run.