Spec drift: polymarket — 15+ new CLOB endpoints not covered by #438 (tick-size, neg-risk, fee-rate, sampling, simplified)

[realfishsam]

Summary

Beyond the 5 endpoints tracked in #438, Polymarket's CLOB API has added 15+ additional endpoints that are not in core/specs/polymarket-clob.yaml. These cover tick-size configuration, negative-risk market handling, fee-rate queries, sampling markets, and simplified market views.

Impact

MEDIUM — these endpoints represent significant new API surface. Without them in the spec, PMXT cannot use callApi() to access them, and missing tick-size/fee-rate data may cause incorrect order construction.

Details

Missing endpoint groups:

1. Tick size: GET /tick-size — returns tick size per market condition ID; needed for correct price rounding
2. Negative risk: GET /neg-risk, POST /neg-risk/convert — neg-risk market metadata and position conversion
3. Fee rate: GET /fee-rate — current taker/maker fee rates for the authenticated address
4. Sampling markets: GET /sampling-markets, GET /sampling-simplified-markets — reduced market sets for sampling use cases
5. Simplified markets: GET /simplified-markets — condensed market list with fewer fields, for performance
6. Market book snapshots: GET /books (batch) — multi-market orderbook snapshot in one call
7. Midpoint prices: GET /midpoints — batch midpoint prices for multiple condition IDs
8. Spread: GET /spread, GET /spreads — current bid/ask spread data
9. Price history: GET /prices-history — OHLCV-style price history per market
10. Additional order management: GET /orders (batch status check by array of order IDs)

Required Fix

Add these endpoint groups to core/specs/polymarket-clob.yaml. Prioritize tick-size and fee-rate endpoints as they directly affect order construction correctness.