Add research playbook for EWRL submission (#27)

## Summary
A self-contained walkthrough at `docs/research_playbook.md` covering everything between right-now and the 2026-05-25 EWRL deadline:

- **Step 0:** Merge PR #26 (closes Training Observability)
- **Step 1:** Pre-pilot prep — W&B login, alerts config, compute decision (local vs RunPod ~$110 vs Lambda ~$135), 5-min smoke test
- **Step 2:** Run the 9 pilots — exact commands, suggested order (pixel → symbolic → hybrid), `tmux` tip, "when to kill a run early" rules, per-run checklist template
- **Step 3:** Analyze with `scripts/compare.py` + `scripts/analyze.py`
- **Step 4:** Draft the EWRL paper (Claude does most; me on review/polish)
- **Step 5:** Parallel research ops — Oracle IP review (must precede arXiv preprint), NCSA ACCESS grant, NC State advisor outreach

Includes a timeline arithmetic section showing ~14 days of slack against the deadline if pilots take 10 days, plus a quick-reference command cheat sheet at the end.

## Test plan
- [x] `cat docs/research_playbook.md` renders cleanly
- [ ] Walking through Step 1 commands once — verify smoke test launches and Streamlit dashboard updates

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Author: amcheste