Fix remaining Forgejo compatibility issues

- Update context variables from github.* to forge.* syntax
- Simplify matrix strategy to remove unsupported os/rust variables
- Standardize runs-on to ubuntu-latest for all jobs
- Add summary creation steps for better workflow feedback
- Ensure all workflows use pure Forgejo-compatible syntax

.forgejo/workflows/build.yml

@@ -355,9 +355,9 @@ jobs:
           
           ## Build Information
           - **Build Date**: $(date '+%Y-%m-%d %H:%M:%S UTC')
-          - **Build ID**: ${{ github.run_id }}
-          - **Commit**: ${{ github.sha }}
-          - **Branch**: ${{ github.ref_name }}
+          - **Build ID**: ${{ forge.run_number }}
+          - **Commit**: ${{ forge.sha }}
+          - **Branch**: ${{ forge.ref_name }}
           
           ## Build Status
           - **Status**: ✅ SUCCESS