Make hooks staged-only and green

Scope

• ✅ lefthook uses {staged_files} for lint/format/test (DONE)
• ✅ Added test:staged script for targeted testing (DONE)
• ✅ Installed ESLint dependencies (@typescript-eslint/*) (DONE)
• ⏳ Verify commit of wiki files passes in CI

Done When

• Hooks check only staged files
• ESLint dependencies installed
• test:staged script added
• Wiki manager commit passes in CI pipeline

Notes

Local pre-commit hooks are working correctly. Need to verify CI pipeline accepts the commit.