docs: add Alpha-tier routing CTA to README

Routes to flashalpha.com/for-quant-teams with a per-repo utm_campaign so Alpha
conversions are attributable per repository.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

Author: tdobrowolski1

README.md

@@ -239,3 +239,9 @@ Get your API key at [flashalpha.com](https://flashalpha.com).
 ## License
 
 MIT
+
+## Beyond the basics
+
+This repo computes the math from scratch and against the live API. Production
+workloads (full-universe coverage, point-in-time history, aggregate vanna/charm)
+run on the **Alpha tier**: [flashalpha.com/for-quant-teams](https://flashalpha.com/for-quant-teams?utm_source=github&utm_medium=readme&utm_campaign=repo-volatility-surface-python)