README: reference the structured press coverage layer (market x polls x press now backed by news CSV)

Add structured press coverage layer (news/uk-2024-press-coverage.csv): 5 dated headlines from 5 national outlets across the cycle (EN). Sourced via Wikipedia-cited articles. Makes the third axis (market x polls x press) a data layer.

Mention structural-context.csv (World Bank WGI + WDI) in dataset card

Add structural-context.csv (World Bank WGI governance + WDI economy & education); document in DATA_DICTIONARY

Add structural-context.csv (World Bank WGI governance + WDI economy & education); document in DATA_DICTIONARY

Dual license CC BY 4.0 + Apache 2.0 in frontmatter

AFOS UK 2024 Electoral Divergence dataset (prediction market vs polls)