Add git practices section to development guide

Document clean history principles:
- Never amend, rebase, or force push
- Use merge to integrate changes
- Keep commits focused and atomic

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

1 files changed, 21 insertions, 0 deletions

diff --git a/DESIGN.md b/DESIGN.md
index 32e2d15..87c1f3c 100644
--- a/DESIGN.md
+++ b/DESIGN.md
@@ -544,6 +544,27 @@ func TestHandler_HandleDashboard(t *testing.T) {
 5. **Don't add unnecessary comments** - Code should be self-explanatory
 6. **Don't create new files unless necessary** - Prefer editing existing
 7. **Don't refactor working code** - Only touch what's needed
+8. **Don't alter git history** - Never amend, rebase, or force push. Keep a clean, linear history with new commits only.
+
+### Git Practices
+
+**Clean history principles:**
+- **Never amend commits** - Create new commits for fixes instead
+- **Never rebase** - Use merge to integrate changes
+- **Never force push** - All pushes should be fast-forward only
+- **One logical change per commit** - Keep commits focused and atomic
+
+**Commit message format:**
+```
+Short summary (50 chars or less)
+
+Optional longer description explaining the why, not the what.
+Reference bug numbers with #N format.
+
+Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>
+```
+
+**If history diverges:** Use `git pull --rebase=false` to merge, never force push.
 
 ### Bug Management Workflow