Migrate twenty-companion from npm to yarn workspaces (#18946)

## Summary
- Migrates twenty-companion from standalone npm to the repo yarn
workspaces
- Removes package-lock.json (resolves Oneleet security finding about npm
lifecycle scripts)
- Converts npm overrides to yarn resolutions
- Updates scripts from npm run to yarn

## Test plan
- [x] Verified yarn install succeeds at root
- [x] Verified yarn start in twenty-companion launches the Electron app
- [ ] Verify Oneleet finding is resolved after merge

package.json

@@ -211,7 +211,8 @@
       "packages/twenty-apps",
       "packages/twenty-cli",
       "packages/create-twenty-app",
-      "packages/twenty-oxlint-rules"
+      "packages/twenty-oxlint-rules",
+      "packages/twenty-companion"
     ]
   },
   "prettier": {