The recent_blocks_cache can contain blocks in two formats:
  - Full format: {"block": {...}, "transaction_receipts": [...]}
  - Light format: just block fields (no wrapper)

  This happens because different code paths populate the cache with
  different formats (upsert_block uses full, blocks_from_store uses light).

  Changes:
  - load_blocks/parent_ptr: Extract block data from full format if needed
    using `value.get("block").unwrap_or(&value)`
  - ancestor_block: Explicit check for light format with clear logging,
    falls back to Firehose/RPC since receipts are needed for triggers
  - Improved log messages to show block number and hash on failures