[Cursor] Fix: git stack create now properly renames branch instead of creating duplicate

Problem: When converting an existing branch to a stack branch using 'git stack create', the original branch was left behind, creating a duplicate branch with -0 suffix.

Solution: Modified create_branch function to use git branch -m to rename the branch instead of creating a new one with git checkout -b. Added test case to verify the original branch is properly renamed.

Author: Dag Jomar Mersland

bin/gitstack.sh

@@ -83,7 +83,7 @@ function create_branch() {
       exit 0
     fi
 
-    # Create new stack branch
+    # Create new stack branch by renaming current branch
     local new_branch="${current_branch}-0"
 
     # Check if the new branch already exists
@@ -92,13 +92,13 @@ function create_branch() {
       exit 1
     fi
 
-    echo "Creating stack branch: $new_branch"
-    if ! git checkout -b "$new_branch"; then
-      echo "Error: Failed to create branch '$new_branch'."
+    echo "Converting branch to stack branch: $new_branch"
+    if ! git branch -m "$new_branch"; then
+      echo "Error: Failed to rename branch to '$new_branch'."
       exit 1
     fi
 
-    echo "Branch '$new_branch' successfully created and checked out."
+    echo "Branch successfully converted to '$new_branch'."
     return 0
   fi
 

bin/gitstack_test.sh

@@ -435,6 +435,13 @@ function test_convert_to_stack() {
     fail "Failed to convert branch to stack, got '$current'"
   fi
 
+  # Verify the original branch no longer exists
+  if git rev-parse --verify dj/my-feature &>/dev/null; then
+    fail "Original branch 'dj/my-feature' still exists after conversion"
+  else
+    echo "✅ Original branch 'dj/my-feature' was properly renamed"
+  fi
+  
   git checkout main 2>/dev/null || git checkout master 2>/dev/null
   git branch -D dj/my-feature-0
 }