skill-find

When the user asks which skill/command/agent fits an intent, find the
best match via qmd's hybrid BM25 + vector search over the skills collection.

1. Check + query with the intent text (substitute it for <intent>):

   bash scripts/skill-index/skill-find.sh "<intent>" 5

   Checks the skills qmd collection is registered and non-empty before
   querying, and goes through the scripts/lib/qmd-bin.sh resolver — bare
   qmd resolves to the broken plugin-cache stub. On exit 3 the collection
   is missing/empty: the script prints the two rebuild commands on stderr —
   run them verbatim, then retry. Never fall back to guessing skill/command
   names (HIMMEL-2222). Re-run the rebuild commands after plugin
   install/uninstall too.

2. Report the top matches: <qualified-name> (e.g. pr-review-toolkit:code-reviewer),
   <kind> (command|agent|skill), <plugin> (or local). See .claude/commands/skill-find.md.