Deduplicate flashloan matches in NFT wash trades

[jeff-dude]

Description:

What & why

Deduplicate flashloan matches by unique_trade_id before joining them to NFT trades.
One NFT trade can match several flashloan rows from the same transaction.
The trade keeps its flashloan flag, and the output no longer fans out into duplicate merge keys.

Architecture

• dbt_subprojects/hourly_spellbook/macros/_sector/nft/nft_wash_trades.sql - data critical path to nft.wash_trades; filter_5 now emits one row per trade ID.
• Validation: PR CI passed and built all 19 chain models. Ethereum completed both full refresh and incremental MERGE; its unique_trade_id test passed. Query of the Ethereum PR CI table returned zero duplicate IDs in the last two days.
• Needs human eyes: CI does not reuse the failed production target state; confirm the next Ethereum hourly build completes.
• Blast radius: all 19 chain wrappers call this macro and receive the fix. The published nft.wash_trades schema and flags stay the same; duplicate flashloan matches collapse to one row.

Agent context

• Coverage ledger: No agent review yet.
• Reproduction context: Slack failure alert
• CI table: dune.dune_spellbook_ci__tmp_pr10047_36318857788_1.nft_ethereum_wash_trades