fix(ci): recover corrupt SDK downloads

.gitea/workflows/ci-deploy.yml

@@ -21,12 +21,22 @@ jobs:
         # dir via dotnet-install.sh and retry once on failure, mirroring the
         # npm ci / NuGet retries elsewhere in this workflow.
         run: |
-          install() {
+          if [ -x "$HOME/.dotnet/dotnet" ] && "$HOME/.dotnet/dotnet" --list-sdks | grep -q '^9\.'; then
-            curl -fsSL https://dot.net/v1/dotnet-install.sh -o /tmp/dotnet-install.sh
+            echo "Reusing valid runner-local .NET 9 SDK."
-            rm -rf "$HOME/.dotnet"
+          else
-            bash /tmp/dotnet-install.sh --channel 9.0 --install-dir "$HOME/.dotnet"
+            install() {
-          }
+              local feed="${1:-}"
-          install || ( echo "dotnet install failed ($?) — retrying once..." && install )
+              local -a feed_args=()
+              if [ -n "$feed" ]; then
+                feed_args=(--azure-feed "$feed")
+              fi
+              curl -fsSL https://dot.net/v1/dotnet-install.sh -o /tmp/dotnet-install.sh
+              rm -rf "$HOME/.dotnet"
+              bash /tmp/dotnet-install.sh --channel 9.0 --install-dir "$HOME/.dotnet" "${feed_args[@]}"
+            }
+            install || ( echo "dotnet install failed ($?) — retrying from alternate Microsoft CDN..." \
+              && install https://dotnetcli.azureedge.net/dotnet )
+          fi
           echo "$HOME/.dotnet" >> "$GITHUB_PATH"
           "$HOME/.dotnet/dotnet" --info