search: make descriptions sufficient without the hook

Descriptions for search and using-entire now demand the skill as the FIRST action on research/investigate/search requests, before Glob, Grep, or Read, and say that an empty or unfamiliar working copy is not a reason to skip it (the observed failure mode was orienting in local files first).

Eval changes: the bare-verb cases get a scaffold.sh fixture repo so the agent has code to be tempted by; the previous empty cwd made them fail for the wrong reason. Full suite passes 20/20 runs with the hook removed; corrected before/after numbers are in evals/README.md.