From 3ee6d63c61219850fe7d506bb2d395530416dd48 Mon Sep 17 00:00:00 2001
From: User <onyx@local>
Date: Wed, 15 Oct 2025 19:36:36 -0400
Subject: [PATCH] Fix hardcoded 'main' branch - detect default branch
 dynamically

- Add getDefaultBranchName() method to WorkstreamManager
- Detects repo default by checking HEAD symbolic ref and fallback
- Update CreateWorkstream to use dynamic default branch detection
- Update 'onx new' CLI flag default to empty string
- Manager now determines correct default branch automatically

Fixes bug where 'onx new feature' always used 'main' even when repo
uses 'master' as the default branch. Now workstreams correctly detect
and use the repository's actual default branch.