Add contrib-search skill; delegate rector-live-test module discovery to it

[bbrala]

Adds a contrib-search Claude Code skill and thins rector-live-test to delegate its module-discovery steps to it.

Drupal.org issue: https://git.drupalcode.org/project/rector/-/work_items/3600791

What

• New .claude/skills/contrib-search/ — searches real contrib code for a deprecated pattern via the api.tresbien.tech index, with two exit points:
  • Quick mode (default): one query → hit count + a few decoded example call sites. Answers "is this pattern present in real contrib, and how widespread?" — the lookup used when judging whether a rector false-positive is a realistic risk, or picking a real module to extract a PHPStan message from.
  • Full mode (--full): additionally filters hits to D11-compatible modules ranked by install count, producing a list ready to live-test.
• rector-live-test — steps 1–3 (search + D11 filter) replaced by a delegation to contrib-search --full; downstream steps renumbered.

Notes

• Scope is contrib-only (every query includes -r:drupal); the skill does not search core.
• No Drupal GitLab blob-search fallback (removed from rector-live-test as part of this change).

🤖 Generated with Claude Code

https://claude.ai/code/session_0153kR3PpEfgVy6x9zNp2UvS