chore(skills): drop find-skills — unused, and its update step began timing out

RC fix (soak day 1): `make update` step 7.5 failed on a 300s clone timeout
of alchaincyf/find-skills. The skill (search the skills.sh registry from
Claude) was never used; the discovery case stays reachable manually via
`npx -y skills find <query>`. Removed from install-plugins.sh (install list
+ summary + comment), update-all.sh (refresh list), link.sh
(NPX_EXTERNAL_SKILLS), lib/toggle-external.sh (MANAGED_TOOLS + case arms),
plugin-advisor.md, .gitignore; local skills/find-skills symlink deleted.
Memory-registry and test-fixture mentions kept — append-only history.
toggle-external `list` verified post-removal; suites 8/8.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01XpphkdTosUzokBDNG7PToS

install-plugins.sh

@@ -832,7 +832,6 @@ echo ""
 
 NPX_SKILLS=(
   "alchaincyf/darwin-skill"
-  "alchaincyf/find-skills"
 )
 
 # `skills add` resolves its target (.agents/skills/, skills-lock.json) RELATIVE
@@ -985,7 +984,7 @@ echo ""
 # STEP 10 — REFRESH SYMLINKS (final, so this script is self-sufficient)
 # ============================================================
 # Steps 2/8/8.5 INSTALL skills (gstack submodule, emil/frontend/motion, npx
-# darwin/find-skills) that link.sh must symlink into ~/.claude/skills/. Since
+# darwin-skill) that link.sh must symlink into ~/.claude/skills/. Since
 # link.sh runs BEFORE this script in install.sh, those symlinks would be missing
 # on a fresh run until link.sh is run again by hand. Re-run it here so
 # `make plugin` (and `make install`) finish complete — nothing left to do.
@@ -1023,7 +1022,6 @@ echo "    🔄 frontend-design     — distinctive frontend interfaces, anti-AI-
 echo "    🔄 impeccable          — /impeccable design verbs + 45-rule deterministic detector (npx impeccable detect)"
 echo "    🔄 design-motion-principles — motion/animation design, 3-designer lens (kylezantos)"
 echo "    🔄 darwin-skill        — autonomous skill optimizer (npx skills, ~/.agents/skills/)"
-echo "    🔄 find-skills         — skill discovery helper (npx skills, ~/.agents/skills/)"
 echo "    🔄 magic MCP           — 21st-dev UI generation MCP (toggle: lib/toggle-external.sh enable magic)"
 echo ""
 echo "  All plugins installed at: user scope (~/.claude/plugins/)"