fix(analytics/ prototype): detect in-flight auctions as missed, remove bidWon

[MO-Thibault]

Summary

• Fix missed auction detection: auctions that fired auctionInit before our analytics hook was set, but whose auctionEnd arrives after, are now correctly marked as missed=true. Previously only fully-completed past auctions (both auctionInit and auctionEnd in getEvents()) were caught.
• Remove bidWon tracking: the trackBidWon method and all bidWon event listeners (replay + live) are removed — no longer needed.

How it works

1. On init, replay past events in a single pass: collect auctionInit IDs into missedAuctionIds, then when an auctionEnd is encountered, remove from set and process as missed.
2. Any IDs remaining in missedAuctionIds after replay are auctions that started but haven't ended yet (in-flight).
3. Live auctionEnd listener checks missedAuctionIds — if the auction ID is present, it's an in-flight auction we missed, so it's marked missed=true and removed from the set.

Test plan

• Deploy to a test page where the SDK loads after Prebid has already started auctions
• Verify in-flight auctions (auctionInit fired, auctionEnd not yet fired at hook time) are marked missed=true in witness payload
• Verify auctions that start after hook is set are marked missed=false
• Verify no bid_won witness events are emitted

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