fix: Add contents:write permission for release uploads

- GitHub Actions needs explicit contents:write permission to upload assets
- Fixes 403 Forbidden error when uploading AppImage to releases
- Both workflow files updated with permissions block

Author: joseph

.github/workflows/multi-format-release.yml

@@ -6,6 +6,9 @@ on:
       - 'v*.*.*'
   workflow_dispatch:
 
+permissions:
+  contents: write  # Required for uploading release assets
+
 jobs:
   build:
     strategy:

.github/workflows/release.yml

@@ -6,6 +6,9 @@ on:
       - 'v*.*.*'  # Triggers on version tags like v1.0.0
   workflow_dispatch:  # Allows manual trigger
 
+permissions:
+  contents: write  # Required for uploading release assets
+
 jobs:
   build-appimage:
     runs-on: ubuntu-22.04