fix: Increase Strictness of Rollback Check

[Step7750]

Now that items don't receive a trade cooldown on reversal, their asset ID doesn't change either.

This change scopes the check to also ensure that the buyer/seller pair is aligned as well.

Ref CSF-1401

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Note

Medium Risk
Moderate risk because it changes how rollback and cancel pings are correlated to CSFloat trades; overly strict matching could miss legitimate rollbacks, while insufficient data (HTML-parsed history) may reduce detection in fallback paths.

Overview
Improves rollback detection by scoping matches to both the traded asset_id and the expected buyer/seller counterparty, reducing false positives now that rollbacks may keep the same asset ID.

Adds other_party_id to TradeHistoryStatus (populated from the Steam API response) and uses it in rollback.ts and trade_offer.ts when correlating Steam trade-history rollbacks to pending CSFloat trades.

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