Add git worktrees documentation to README

Document the worktree setup for parallel experiment development.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

README.md

@@ -125,6 +125,29 @@ Experiments are tracked manually in `results/{task}/README.md`:
 4. Create numbered notebooks
 5. Add entry to `results/my_task/README.md`
 
+## Git Worktrees
+
+This repository uses git worktrees for parallel experiment development:
+
+| Worktree | Branch | Purpose |
+|----------|--------|---------|
+| `alpha_lab` | `master` | Main repo (reference) |
+| `alpha_lab_cta_1d` | `cta_1d_exp` | CTA 1-day experiments |
+| `alpha_lab_stock_1d` | `stock_1d_exp` | Stock 1-day experiments |
+| `alpha_lab_stock_15m` | `stock_15m_exp` | Stock 15-min experiments |
+| `alpha_lab_data_ops` | `data_ops_exp` | Data ops research |
+
+```bash
+# Create a new worktree
+git worktree add ../alpha_lab_new_exp -b new_exp
+
+# List all worktrees
+git worktree list
+
+# Remove a worktree when done
+git worktree remove ../alpha_lab_new_exp
+```
+
 ## Best Practices
 
 1. **Keep it simple**: Only add to `common/` after 3+ copies