Add packages write permission to workflows

GitHub Actions workflows need explicit permissions to push to GHCR.
Added:
  permissions:
    contents: read
    packages: write

This fixes the "installation not allowed to Create organization package" error.

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude <noreply@anthropic.com>

Author: jcrapuchettes

.github/workflows/ci.yaml

@@ -7,6 +7,9 @@ jobs:
   release:
     if: ${{ startsWith(github.ref, 'refs/tags/v') }}
     runs-on: ubuntu-latest
+    permissions:
+      contents: read
+      packages: write
     strategy:
       matrix:
         pg_version:

.github/workflows/push.yml

@@ -80,6 +80,9 @@ jobs:
     runs-on: ubuntu-latest
     needs: [build, unit, staticcheck, errcheck]
     if: github.event_name == 'push' && github.ref == 'refs/heads/master'
+    permissions:
+      contents: read
+      packages: write
     strategy:
       matrix:
         pg_version: