ci: retry every buzz-agent integration test in place (merge-queue races)

[wiggdevin]

Summary

Follow-up to #39. A second steer-timing test, handoff_cap_binds_within_a_single_turn (crates/buzz-agent/tests/regressions.rs), ejected PR #35 from the merge queue (run 34126777445) three minutes into the unit job. The same tree passed the whole unit lane in the next queue run (34127545692, for #39). Neither test is touched by #35.

What changed

.config/nextest.toml: the per-test override from #39 becomes a family override, package(buzz-agent) and kind(test) with retries = 2. The buzz-agent integration tests drive a spawned agent over a fake LLM and read a bounded number of frames, so frame order under load decides pass or fail. A genuine regression still fails every attempt. The older per-test override for cancelled_turn_with_usage_emits_notification_before_response stays as it is.

Gates run

• TOML parses; the default profile lists both overrides.
• Pre-push hook (lefthook) lanes green.
• No full suite run locally; the queue runs it.

🤖 Generated with Claude Code
https://claude.ai/code/session_01P8VoJ9givMm44HNc4gx5Gz

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