fix: resolve YAML syntax errors in integrate-develop.yml

- Replace problematic heredoc with echo command approach
- Fix indentation and syntax errors
- Remove trailing spaces
- All workflow files now pass yamllint validation

Author: Seungwoo321

.github/workflows/integrate-develop.yml

@@ -130,24 +130,15 @@ jobs:
           # Get current PR body
           CURRENT_BODY=$(gh pr view $PR_NUMBER --json body --jq '.body')
 
-          # Create updated section with escaped content
-          cat > updated-section.md << 'EOF'
-### 🔄 Last Updated: TIMESTAMP_PLACEHOLDER
-New commits: COUNT_PLACEHOLDER
-
-### 📝 Recent Commits
-COMMITS_PLACEHOLDER
-EOF
-          
-          # Replace placeholders safely
-          sed -i "s/TIMESTAMP_PLACEHOLDER/${TIMESTAMP}/g" updated-section.md
-          sed -i "s/COUNT_PLACEHOLDER/${COMMIT_COUNT}/g" updated-section.md
-          
-          # Process commits separately and safely
-          echo "${COMMITS}" | sed 's/%0A/\n/g' | sed 's/%0D//g' | sed 's/%25/%/g' > commits-temp.txt
-          sed -i '/COMMITS_PLACEHOLDER/r commits-temp.txt' updated-section.md
-          sed -i '/COMMITS_PLACEHOLDER/d' updated-section.md
-          
+          # Create updated section safely using echo commands
+          {
+            echo "### 🔄 Last Updated: ${TIMESTAMP}"
+            echo "New commits: ${COMMIT_COUNT}"
+            echo ""
+            echo "### 📝 Recent Commits"
+            echo "${COMMITS}" | sed 's/%0A/\n/g; s/%0D//g; s/%25/%/g'
+          } > updated-section.md
+
           UPDATED_SECTION=$(cat updated-section.md)
 
           # Update or append the updated section