Enhance release notes extraction to prioritize CHANGELOG section and support new format

Author: MishaKav

.github/workflows/create-tag-on-merge.yml

@@ -41,14 +41,29 @@ jobs:
               const pull_number = prs[0].number;
               const { data: pr } = await github.rest.pulls.get({ owner, repo, pull_number });
               
-              // Extract content between gitstream placeholders, excluding header and footer
+              // Extract content from PR description - prioritize CHANGELOG if present
               let releaseNote = pr.title;
 
               if (pr.body) {
-                const contentMatch = pr.body.match(/<!--start_gitstream_placeholder-->.*?### ✨ PR Description\s*(.*?)\s*_Generated by LinearB AI.*?<!--end_gitstream_placeholder-->/s);
-
-                if (contentMatch) {
-                  releaseNote = contentMatch[1].trim();
+                // First, check for __CHANGELOG__ section
+                const changelogMatch = pr.body.match(/__CHANGELOG__\s*(.*?)\s*_Generated by LinearB AI/s);
+                
+                if (changelogMatch) {
+                  releaseNote = changelogMatch[1].trim();
+                } else {
+                  // Fallback to original gitstream placeholder extraction
+                  const contentMatch = pr.body.match(/<!--start_gitstream_placeholder-->.*?### ✨ PR Description\s*(.*?)\s*_Generated by LinearB AI.*?<!--end_gitstream_placeholder-->/s);
+                  
+                  if (contentMatch) {
+                    releaseNote = contentMatch[1].trim();
+                  } else {
+                    // New format without gitstream placeholders
+                    const newFormatMatch = pr.body.match(/## ✨ PR Description\s*(.*?)\s*(?:__CHANGELOG__|_Generated by LinearB AI)/s);
+                    
+                    if (newFormatMatch) {
+                      releaseNote = newFormatMatch[1].trim();
+                    }
+                  }
                 }
               }