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": {

packages/twenty-companion/package.json

@@ -5,7 +5,7 @@
   "description": "Twenty meeting recorder",
   "main": ".webpack/main",
   "scripts": {
-    "start": "concurrently \"npm run start:server\" \"npm run start:electron\"",
+    "start": "concurrently \"yarn start:server\" \"yarn start:electron\"",
     "start:electron": "electron-forge start",
     "package": "electron-forge package",
     "make": "electron-forge make",
@@ -37,10 +37,8 @@
     "node-loader": "^2.1.0",
     "style-loader": "^3.3.4"
   },
-  "overrides": {
-    "@electron/packager": {
-      "@electron/osx-sign": "github:recallai/osx-sign"
-    }
+  "resolutions": {
+    "@electron/packager/@electron/osx-sign": "github:recallai/osx-sign"
   },
   "dependencies": {
     "@anthropic-ai/sdk": "^0.40.1",