feat: upload release artifacts to Volcengine TOS (#1164)

Add reusable workflow (upload-tos.yml) to upload release archives to
Volcengine TOS bucket. Supports both workflow_call from release pipeline
and manual workflow_dispatch trigger. Uploads to versioned ({tag}/) and
latest/ directories.

Co-authored-by: Claude Opus 4.6 <noreply@anthropic.com>

.github/workflows/release.yml

@@ -100,3 +100,11 @@ jobs:
           gh release edit "${{ inputs.tag }}" \
             --draft=${{ inputs.draft }} \
             --prerelease=${{ inputs.prerelease }}
+
+  upload-tos:
+    name: Upload to TOS
+    needs: release
+    uses: ./.github/workflows/upload-tos.yml
+    with:
+      tag: ${{ inputs.tag }}
+    secrets: inherit