LICENSE, camera-ready checklist, and a full proofread pass

[duckyquang]

Three small items:

1. LICENSE: propose MIT vs Apache-2.0 in a comment here for a quick lab decision, then commit it (the artifact reviewer flagged the absence).
2. AAAI checklist: fill the reproducibility-checklist answers against the actual repo (they ask specifics: code released? seeds? CIs? compute used?) and put the draft answers in paper/CHECKLIST.md so submission day is copy-paste.
3. Proofread marc_aaai.pdf end to end: typos, notation drift (q(n) vs q_n, K vs k), table/figure reference correctness, caption completeness. File everything as ONE review comment on PR Review-board fixes, R28 geometry construction repair, R29 oracle control, AAAI port #118 rather than editing the tex (I integrate in Final integration, page budget, and the regime-map promotion #122 to avoid collisions).

Est half a day to a day.