fix: remaining npm→pnpm gaps + dockerignore for pnpm symlinks

- container/.dockerignore (new): exclude agent-runner/node_modules and
  agent-runner/dist so COPY agent-runner/ ./ doesn't clobber the
  pnpm-installed node_modules with host directories. Under npm's flat
  layout this was forgiving; under pnpm's symlink layout it's a hard
  conflict (overlay2 cannot copy onto a symlink target).
- setup/{groups,service}.ts: execSync('pnpm run build') not npm.
- setup/index.ts: usage string.
- scripts/*.ts: usage comments + seed-discord final log.
- .claude/settings.json: permission allowlist entries.
- .claude/skills/{add-whatsapp-v2,add-dashboard}/SKILL.md: docs.
- container/skills/{frontend-engineer,vercel-cli,self-customize}/SKILL.md:
  agent-facing docs still told the container agent to run npm.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

container/skills/vercel-cli/SKILL.md

@@ -117,7 +117,7 @@ After sending, tell the user you've handed it off and will share the result when
 
 ## Best Practices
 
-- Run `npm run build` locally before deploying to catch build errors early
+- Run `pnpm run build` locally before deploying to catch build errors early
 - Use `--cwd` instead of `cd` to keep your working directory stable
 - For Next.js projects, `vercel deploy` auto-detects the framework — no extra config needed
 - Use `vercel.json` only when you need custom build settings, rewrites, or headers