fix: strip newlines from SSH_KEY_PUBLIC secret in workflows

Normalize SSH public key secret before writing secrets.auto.tfvars so wrapped/multiline key pastes do not break Terraform parsing.

.gitea/workflows/terraform-plan.yml

@@ -25,7 +25,7 @@ jobs:
           echo "PM_API_TOKEN_SECRET length: $(echo -n '${{ secrets.PM_API_TOKEN_SECRET }}' | wc -c)"
           cat > secrets.auto.tfvars << EOF
           pm_api_token_secret = "${{ secrets.PM_API_TOKEN_SECRET }}"
-          SSH_KEY_PUBLIC      = "${{ secrets.SSH_KEY_PUBLIC }}"
+          SSH_KEY_PUBLIC      = "$(printf '%s' "${{ secrets.SSH_KEY_PUBLIC }}" | tr -d '\r\n')"
           EOF
           cat > backend.hcl << EOF
           bucket                      = "${{ secrets.B2_TF_BUCKET }}"