Add FXMacroData release-calendar integration

[roberttidball]

Summary

• add a read-only FXMacroData integration for official-source macro release-calendar data
• use the public https://fxmacrodata.com/api/v1/calendar/{currency} endpoint with optional FXMACRODATA_API_KEY
• support event-risk workflows by exposing release names, dates, timestamps, market tiers, and source metadata

Validation

• git diff --check
• Python helpers: python -m py_compile on changed .py files where applicable
• TypeScript repos: native build/type checks where applicable
• Live smoke: FXMacroData USD calendar helper returned a locally limited set of public top-tier rows

Note: R is not installed in this local environment, so R package changes were reviewed but not executed with R CMD check.