fix(core): type live numeric response fields

[realfishsam]

Summary

• Type Limitless live volume / volumeFormatted payload fields as number | string
• Type Probable live volume24hr / volume / liquidity payload fields as number | string
• Add regression coverage that Polymarket, Limitless, and Probable string numeric fields normalize to numbers

Fixes #1211
Fixes #1212
Fixes #1213

Test Plan

• npm test --workspace=pmxt-core -- --runTestsByPath test/normalizers/exchange-normalizers.test.ts test/normalizers/exchange-normalizers-2.test.ts (300 passed)
• npm run build --workspace=pmxt-core

[realfishsam]

Validation update:

• Targeted local checks pass:
  • npm test --workspace=pmxt-core -- --runTestsByPath test/normalizers/exchange-normalizers.test.ts test/normalizers/exchange-normalizers-2.test.ts (300 passed)
  • npm run build --workspace=pmxt-core
• The PR is mergeable and scoped to numeric response field typing/regression tests for Response drift: polymarket — markets[].liquidity and .volume are strings; passed through without numeric conversion #1211, Response drift: limitless — data[].volume and .volumeFormatted are strings; passed through without numeric conversion #1212, and Response drift: probable — markets[].volume24hr and .liquidity are strings; passed through without numeric conversion #1213.
• GitHub generated-sync checks are currently red on unrelated pre-existing generated drift: API reference/sourceExchange docs, COMPLIANCE Hunch section, hosted client-method preservation, and missing Hunch SDK/OpenAPI exchange surfacing. I did not fold that broad unrelated generator drift into this focused response-drift PR.

[realfishsam]

PR Review: PASS (NOT VERIFIED)

What This Does

Updates the core raw venue TypeScript models so live numeric fields that arrive as strings from Limitless and Probable are typed as number | string. This matters to SDK consumers because the existing normalizers already coerce those fields to numeric unified volume / liquidity values, and the raw types now match the venue payloads instead of forcing casts.

Blast Radius

Core exchange raw types for Limitless and Probable plus normalizer regression tests. No OpenAPI schema, SDK shim, auth, router, or generated SDK files are changed.

Consumer Verification

Before (base branch):
Static contract only: the old raw interfaces modeled LimitlessRawMarket.volumeFormatted, LimitlessRawMarket.volume, ProbableRawMarket.volume24hr, ProbableRawMarket.volume, and ProbableRawMarket.liquidity as number only, even though the PR fixtures describe live venue responses where those fields can be strings. I did not run a live consumer API before/after because this PR changes TypeScript source typing/test coverage, not runtime normalization logic.

After (PR branch):
Static contract now accepts the observed response drift:

// core/src/exchanges/limitless/fetcher.ts
volumeFormatted?: number | string;
volume?: number | string;

// core/src/exchanges/probable/fetcher.ts
volume24hr?: number | string;
volume?: number | string;
liquidity?: number | string;

Focused normalizer tests confirm string numeric fixtures still normalize to number-valued unified fields.

Test Results

• Build: PASS (npm run build --workspace=pmxt-core)
• Unit tests: PASS (300 passed, 0 failed: test/normalizers/exchange-normalizers.test.ts, test/normalizers/exchange-normalizers-2.test.ts)
• Server starts: PASS (GET /health succeeded on local sidecar)
• E2E smoke: NOT VERIFIED (no live venue/API consumer delta; runtime code path is unchanged)

Findings

No blocking findings.

PMXT Pipeline Check

• Field propagation (3-layer): N/A — no unified field or schema change; raw input typing only
• OpenAPI sync: N/A
• Financial precision: OK — no new arithmetic; existing normalizer coercion is covered by tests
• Type safety: OK — raw interfaces now match observed string-or-number venue payloads
• Auth safety: N/A

Semver Impact

patch -- type accuracy/regression coverage for existing normalized fields, with no public response-shape change.

Risk

Live venue verification was not performed, so this review verifies the static type contract and normalizer behavior rather than a live Limitless/Probable sidecar response.