Summary

• defer native FFF creation until the first find, glob, or grep
• share one cached initialization across concurrent first searches
• keep picker cleanup attached to the location scope
• cover lazy creation, concurrent initialization, reuse, and destruction with the real native picker

This prevents opening or restoring VCS-backed locations from immediately building FFF content indexes when no filesystem search is performed.

Test plan

• bun run test test/filesystem/search.test.ts from packages/core
• bun run test from packages/core
• bun typecheck from packages/core
• repository pre-push typecheck