Add automatic GitHub Discussions post for stable releases

Configure release workflow to automatically create a discussion post
in the CI-CD category when stable releases are published.

**Changes:**
- Conditionally add --discussion-category ci-cd flag to gh release create
- Only applies to stable releases (not nightly or development builds)

**Category ID:** DIC_kwDOACA_5s4Cxk-W

This matches the pattern used in zlmdb and cfxdb for automated
release announcements.

Author: oberstet

.github/workflows/release.yml

@@ -1667,18 +1667,21 @@ jobs:
           # Delete existing release if it exists (for nightly builds)
           gh release delete "$RELEASE_NAME" --repo "$GITHUB_REPOSITORY" --yes || true
 
-          # Set release title based on type
+          # Set release title and discussion category based on type
           if [ "$RELEASE_TYPE" = "stable" ]; then
             TITLE="Release $RELEASE_NAME"
+            DISCUSSION_FLAG="--discussion-category ci-cd"
           else
             TITLE="Nightly Build $RELEASE_NAME"
+            DISCUSSION_FLAG=""
           fi
 
           # Create the release using rendered notes
           gh release create "$RELEASE_NAME" \
             --repo "$GITHUB_REPOSITORY" \
             --title "$TITLE" \
             --notes-file release-notes.md \
+            $DISCUSSION_FLAG \
             release-artifacts/*
 
           echo "✅ Release $RELEASE_NAME created successfully"