feat: migrate all downloads to R2 CDN with race_download

- Remove update.hwdns.net proxy, add dl.dbxio.com R2 CDN
- Remove deprecated race_github_proxies, replace with race_download
- Update Tauri updater endpoints to prioritize R2
- Migrate update check, JDBC plugin download to race_download
- Add R2 upload job to publish-packages workflow

.github/workflows/publish-packages.yml

@@ -215,3 +215,43 @@ jobs:
             git push
             echo "::notice::Scoop manifest updated to ${VERSION}"
           fi
+
+  upload-r2:
+    name: Upload to R2
+    runs-on: ubuntu-latest
+    if: ${{ github.event_name == 'workflow_dispatch' || (!github.event.release.draft && !github.event.release.prerelease) }}
+    steps:
+      - name: Extract version from tag
+        id: version
+        run: |
+          TAG="${{ github.event.release.tag_name || github.event.inputs.tag }}"
+          TAG="$(echo "${TAG}" | xargs)"
+          echo "tag=${TAG}" >> "$GITHUB_OUTPUT"
+
+      - name: Download release assets
+        env:
+          GH_TOKEN: ${{ secrets.GITHUB_TOKEN }}
+        run: |
+          mkdir -p assets
+          gh release download "${{ steps.version.outputs.tag }}" \
+            --repo "${{ github.repository }}" \
+            --dir assets \
+            --clobber
+          ls -lh assets/
+
+      - name: Upload to R2 (versioned)
+        run: |
+          aws s3 sync ./assets "s3://${{ secrets.R2_BUCKET_NAME }}/releases/${{ steps.version.outputs.tag }}/" \
+            --endpoint-url "https://${{ secrets.R2_ACCOUNT_ID }}.r2.cloudflarestorage.com"
+        env:
+          AWS_ACCESS_KEY_ID: ${{ secrets.R2_ACCESS_KEY_ID }}
+          AWS_SECRET_ACCESS_KEY: ${{ secrets.R2_SECRET_ACCESS_KEY }}
+
+      - name: Upload to R2 (latest)
+        run: |
+          aws s3 sync ./assets "s3://${{ secrets.R2_BUCKET_NAME }}/releases/latest/" \
+            --endpoint-url "https://${{ secrets.R2_ACCOUNT_ID }}.r2.cloudflarestorage.com" \
+            --delete
+        env:
+          AWS_ACCESS_KEY_ID: ${{ secrets.R2_ACCESS_KEY_ID }}
+          AWS_SECRET_ACCESS_KEY: ${{ secrets.R2_SECRET_ACCESS_KEY }}