Polymarket CLOB: ignore superseded same-token late deltas without reconnecting

[proerror77]

Parent

#313

Change contract

When the public Polymarket CLOB WebSocket delivers a price-change delta whose source timestamp is older than the already-applied state for the same token, treat that delta as superseded: do not mutate the cached L2 book, do not broadcast it, and continue processing independent entries in the same batch. Keep malformed fields, invalid depth, and crossed final books fail-closed.

Counterexample

Live public wire capture on 2026-07-29 delivered timestamp 1785305941291 for a token followed by 1785305941290. Current market_updates_from_price_change returns an error for the one-millisecond late delta; the caller reconnects and emits quote_collection_failure for every subscribed token, preventing an otherwise usable source-closed segment from becoming canonical.

Acceptance criteria

• A focused test reproduces a mixed batch containing one superseded same-token delta and one current independent-token delta.
• The superseded entry does not mutate or broadcast the older token state.
• The current independent entry is still applied and broadcast.
• A crossed final book and malformed delta remain errors.
• Focused ploy-market-data tests and formatting pass.

Out of scope

Production collector deployment/cutover; ACK Job mutation; uploader retry policy; ResearchSnapshot/evaluator/MCTS; weakening raw canonical or quote-quality policy.

PRD

None. This is a small, already-specified counterexample fix at the existing CLOB payload seam.