fix(core): address spec response drift batch

[realfishsam]

Summary

• surface venue minimum order size/tick-size metadata for Polymarket US and Polymarket CLOB books
• refresh small OpenAPI drift for Polymarket CLOB/Data, Kalshi, and Metaculus specs/generated specs
• correct Hyperliquid allMids HIP-4 lookup keys and unwrap paginated Polymarket trade responses

Issues

Fixes #902
Fixes #901
Fixes #900
Fixes #895
Fixes #893
Fixes #892
Fixes #890
Fixes #887
Fixes #800

Test Plan

• node YAML parse for touched spec files
• npm run build --workspace=pmxt-core

[realfishsam]

PR Review: FAIL

What This Does

Updates venue specs/normalizers for response drift and adds unified market/order-book metadata such as minimum order size and tick size.

Blast Radius

Polymarket specs/API clients/fetcher/normalizer, Polymarket US normalizer, Hyperliquid/Metaculus utils, core/src/types.ts, OpenAPI/docs.

Consumer Verification

Before (base branch):
Base did not expose these new drift fields (for example minOrderSize) in the unified core types. A full before/after sidecar comparison was not run because the PR fails tests.

After (PR branch):
PR adds UnifiedMarket.minOrderSize in core/src/types.ts, but SDK model propagation is incomplete: schema-drift tests report missing minOrderSize in the TypeScript SDK and min_order_size in the Python SDK.

Test Results

• Build: PASS
• Unit tests: FAIL (schema-drift: 2 failed, 642 passed, 3 skipped)
• Server starts: NOT VERIFIED after failing tests
• E2E smoke: FAIL (blocked by schema-drift failure)

Findings

1. core/src/types.ts:92 adds UnifiedMarket.minOrderSize, but sdks/typescript/pmxt/models.ts:43 UnifiedMarket and sdks/python/pmxt/models.py:56 UnifiedMarket do not include the corresponding SDK fields. The repo’s schema-drift test fails with missing minOrderSize / min_order_size, which means SDK consumers would silently lose the new field even though core/OpenAPI expose it.

PMXT Pipeline Check

• Field propagation (3-layer): ISSUE — core type field is not propagated to both SDK model layers
• OpenAPI sync: OK for generated OpenAPI/docs touched in the PR
• Financial precision: N/A
• Type safety: ISSUE — schema-drift tests fail
• Auth safety: N/A

Semver Impact

minor -- adds new response fields, but incomplete SDK propagation blocks merge.

Risk

No consumer-path verification was performed after the failing schema-drift tests; the main production risk is publishing a core field that SDK users cannot see.