fix: don't combine --all with branch name in git log

Using 'git log --all <branch>' creates ambiguous behavior. Now:
- Without branch: uses --all to show all commits from all refs
- With branch: shows only commits from that specific branch

This ensures consistent commit counts between git CLI and API.

apps/api/src/utils/git_history.py

@@ -67,13 +67,14 @@ def get_commit_history(repo_path: str, branch: str | None = None, limit: int = 1
     # Build git log command - use NULL bytes as separators to avoid parsing issues
     log_args = [
         "log",
-        "--all",
         "--format=%H%x00%P%x00%an%x00%ae%x00%at%x00%s",
         f"--max-count={limit}",
         f"--skip={offset}",
     ]
     if branch:
         log_args.append(branch)
+    else:
+        log_args.append("--all")
 
     log_output = _run_git_command(repo_path, log_args)