perf(mcp): prefilter simple suffix globs on Windows

[ertankucukoglu]

What does this PR do?

Prefilters safe simple suffix globs such as *.pas and *.d.ts before PowerShell Select-String on Windows.

Complex patterns continue to use the existing post-filter path, and the final defensive file-pattern filter is preserved.

Adds regression coverage for safe/unsafe pattern boundaries and PowerShell command ordering.

Test results: 7353 passed, 0 failed, 63 skipped.

Part of #1565

Checklist

• Every commit is signed off (git commit -s) — required, CI rejects
  unsigned commits (DCO, see CONTRIBUTING.md)
• Tests pass locally (make -f Makefile.cbm test)
• Lint passes (make -f Makefile.cbm lint-ci)
• New behavior is covered by a test (reproduce-first for bug fixes)

[github-actions]

Thanks for opening this — it has been seen, and it is queued.

This note is automated, but it is not a brush-off: it exists so you know where your PR stands instead of having to guess from silence.

Current review status: working through a backlog. 0.9.1-rc.1 is out, so the release freeze that held reviews is over — but it left a large queue of open pull requests behind it, and we are reading through them oldest-first. The background is in discussion #1144.

What that means for this PR, concretely:

• It will not be closed for inactivity. No stale bot touches pull requests here.
• It may still sit a while before a human reads it. That is on us, not on you.
• Older PRs are read first, so a recent one is not being skipped — it is behind a queue.

Things that will genuinely speed it up whenever review does happen:

• Keep it rebased on main — the tree is moving quickly right now, and a conflicting branch cannot be reviewed as the diff you intended.
• Get CI green, or say which failures you believe are pre-existing.
• Keep the change to one claim. Bundled features and refactors get split before they get merged, which costs you a round trip.
• Every commit needs a sign-off (git commit -s) — CI enforces DCO.

If this fixes a bug, a reproduction we can run is worth more than a description of the symptom.

Thanks for contributing, and sorry in advance for the wait.

[ertankucukoglu]

Could a maintainer please rerun the failed test-lsan-macos job?

The run completed with 7465 passed tests and one failure in an unrelated timing-sensitive lock registry test:

lock_registry_absolute_deadline_survives_repeated_wakes
FAIL tests/test_lock_registry.c:1153: ASSERT(tail_queued)

This PR only changes Windows search_code suffix prefiltering and does not modify the lock registry. The same macOS LSan check passed on the other PRs from the same base, so this appears transient.

[ertankucukoglu]

Rebased onto current main and removed the unrelated comment rewrapping noted in review. The branch remains scoped to the results-preserving Windows suffix prefilter; the push also retriggers the previously flaky macOS LSan check.