docs: convert all skill instructions from npm to pnpm

Batch update 62 files across .claude/skills/ — SKILL.md, REMOVE.md,
and script files. Conversions: npm run -> pnpm run, npm install ->
pnpm install, npx -> pnpm exec/dlx, npm uninstall -> pnpm uninstall,
package-lock.json -> pnpm-lock.yaml, shebangs updated.

.claude/skills/init-onecli/SKILL.md

@@ -231,10 +231,10 @@ Ask them to let you know when done.
 ## Phase 4: Build and restart
 
 ```bash
-npm run build
+pnpm run build
 ```
 
-If build fails, diagnose and fix. Common issue: `@onecli-sh/sdk` not installed — run `npm install` first.
+If build fails, diagnose and fix. Common issue: `@onecli-sh/sdk` not installed — run `pnpm install` first.
 
 Restart the service:
 - macOS (launchd): `launchctl kickstart -k gui/$(id -u)/com.nanoclaw`