land: main-flake-fixes

[aft-alfonso]

Accepted agent delivery; branch-keyed search descriptor included.

---

Summary by cubic

Fixes flaky tests in the aft crate that timed out on loaded Windows runners. The tests now wait on events instead of wall-clock budgets.

Bug Fixes

• The lane-paused search test installs a ready trigram index up front instead of waiting on a background build.
• The reuse-fill cold-cap test waits for either the fill result or a queued waiter on the held limiter, not a 2-second timeout.
• The long-line grep test runs its scan on a frozen clock that advances only when line details are built, while real file reads keep a separate 60-second guard, so it never hits the deadline.
• The storm setup bind now waits for its reply and fails with the refusal body if refused, instead of timing out.
• Adds a benchmark descriptor for these test-only changes.

^{Written for commit 5d22113. Summary will update on new commits.}

Confidence Score: 5/5

The PR appears safe to merge; no blocking issues remain.

Summary

Replaces short timing assumptions with ready test data and event-based waits.

• The paused-search test starts with its keyword index ready.
• The long-line grep test measures scan work with a controllable clock.
• The reuse-fill test waits for a result or a queued limiter request.
• The storm setup waits for the bind reply before checking epochs.

_{Reviews (2) · Last reviewed commit: "mason: separate real read deadlines from..." · Reviewed by Greptile}