New feature, several BEEF correctness fixes, and packaging cleanup
since v0.7.0. See CHANGELOG.md for the full changelog.

Highlights:
  * feat: MerklePath.from_tsc for WhatsOnChain TSC proof conversion (#280)
  * fix: Beef#to_binary correctly deduplicates same-block BUMPs (#288)
  * fix: Beef#to_binary raises clear error on V1 + TXID_ONLY (#290)
  * fix: Beef#merge raises on inconsistent bump_index (#291)
  * fix: Beef#to_hex preserves the parsed BEEF version (#292)
  * chore: bsv-sdk gem no longer ships sub-gem code (98 files vs 144)

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>