Add fragile-index draft

v0.0.2: Non-circular Area Law derivation

Key changes:
- Fixed circularity in Section A.6 microstate counting derivation
- 1/4 coefficient now derived from curvature normalization K=-1
- Added FAQ sections D.11.4 (circularity) and D.12 (Hypostructure gaps)
- Added citations for Strominger-Vafa, Chentsov, Cover-Thomas

Release Hypostructure draft

Full Changelog: https://github.com/Guillemdb/hypostructure/commits/v0.0.1