fix(dev): recheck cancellation after epoch probe (review follow-up #134)

[ScriptedAlchemy]

Summary

• recheck the caller abort signal after the asynchronous epoch availability probe and before MCP tool dispatch
• add a deterministic regression covering cancellation while the epoch probe is pending

Test plan

• pnpm exec rstest run packages/agent-bundle/tests/mcp-session-service.test.ts --config rstest.integration.config.ts
• pnpm typecheck
• pnpm lint

[changeset-bot]

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Latest commit: f23477c

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[chatgpt-codex-connector]

Codex Review Summary

This comment shows the latest Codex review activity on this pull request.

Review	Status	Commit	Review trigger
📝 Code Review	✅ Completed 2026-09-01T18:07:50.380683Z	f23477c	PR opened

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