Improve previous tag detection in auto-release workflow

Replaces 'git describe' with logic to find the previous tag by sorting all tags by creation date. This ensures accurate detection of the previous tag for release note generation and adds error handling if no previous tag is found.

.github/workflows/auto-release.yml

@@ -94,8 +94,24 @@ jobs:
           # 当前 tag
           CURRENT_TAG="${GITHUB_REF#refs/tags/}"
 
-          # 上一个 tag
-          PREV_TAG=$(git describe --tags --abbrev=0 "$CURRENT_TAG^")
+          # 获取所有 tag 按创建时间倒序排列
+          TAGS=( $(git tag --sort=-creatordate) )
+
+          # 找到上一个 tag
+          PREV_TAG=""
+          for i in "${!TAGS[@]}"; do
+            if [ "${TAGS[$i]}" = "$CURRENT_TAG" ]; then
+              if [ $((i+1)) -lt ${#TAGS[@]} ]; then
+                PREV_TAG="${TAGS[$((i+1))]}"
+              fi
+              break
+            fi
+          done
+
+          if [ -z "$PREV_TAG" ]; then
+            echo "❌ Could not find previous tag for $CURRENT_TAG, aborting."
+            exit 1
+          fi
 
           echo "Generating release note from $PREV_TAG to $CURRENT_TAG"