docs: polish pass — README wording, experiment_log structure + honest retrospective, LaTeX micro-style

docs: clean up R3/R4 record and consolidate technical narrative

docs: finalize R4 documentation — Dueling 84% Holdout, full ablation record

docs(round4): finalize R4 Double DQN results — 78% Holdout, Grid-SPL clarification

docs: README — results table, architecture, quickstart, references

docs(round4): complete experiment record — A1/A2/A3 full EVAL data and conclusions