security: harden CI against supply-chain attacks (#20476)

- Pin all third-party actions to SHA
- Gate claude.yml triggers to internal authors with Harden-Runner egress
audit
- Ignore fork-PR lifecycle scripts
- Narrow cross-repo dispatch payloads
- Add 7d npm release-age gate
- Add CODEOWNERS on .github/** and .yarnrc.yml

---------

Co-authored-by: prastoin <paul@twenty.com>

.github/workflows/docs-i18n-push.yaml

@@ -24,7 +24,7 @@ jobs:
     runs-on: ubuntu-latest
     steps:
       - name: Checkout
-        uses: actions/checkout@v4
+        uses: actions/checkout@34e114876b0b11c390a56381ad16ebd13914f8d5 # v4.3.1
         with:
           token: ${{ github.token }}
           ref: ${{ github.ref }}
@@ -36,7 +36,7 @@ jobs:
         run: yarn docs:generate-navigation-template
 
       - name: Upload docs to Crowdin
-        uses: crowdin/github-action@v2
+        uses: crowdin/github-action@8868a33591d21088edfc398968173a3b98d51706 # v2
         with:
           upload_sources: true
           upload_translations: false