[codex] Add Twenty Claude skills package (#20450)

## Summary

Adds a new `twenty-claude-skills` workspace package under `packages/`
for Claude skills related to Twenty.

## Changes

- Registers `packages/twenty-claude-skills` in the root Yarn workspace
list.
- Adds package metadata for `twenty-claude-skills`.
- Adds a README documenting the multi-skill layout.
- Adds the `twenty-record-presentation` skill under
`skills/twenty-record-presentation/SKILL.md`.

## Impact

This gives Claude-specific Twenty skills a dedicated package location
while preserving the skill metadata from the provided skill bundle.

## Validation

- Parsed the root `package.json` and
`packages/twenty-claude-skills/package.json` with Node.
- Compared the imported skill content against the source `.skill`
archive; the only difference is a trailing newline at EOF.

package.json

@@ -63,7 +63,8 @@
       "packages/twenty-cli",
       "packages/create-twenty-app",
       "packages/twenty-oxlint-rules",
-      "packages/twenty-companion"
+      "packages/twenty-companion",
+      "packages/twenty-claude-skills"
     ]
   },
   "prettier": {