fix: add quoteToken to hyperliquid outcome interface

[realfishsam]

Fixes #555

[realfishsam]

PR Review: PASS (NOT VERIFIED)

What This Does

Adds a quoteToken: string field to the HyperliquidRawOutcome interface to capture the settlement currency (e.g., "USDC") from the venue API response.

Blast Radius

• Core layer only: core/src/exchanges/hyperliquid/fetcher.ts (raw type definition)
• No normalizer, OpenAPI schema, or SDK changes

Findings

1. The field is added to the raw venue-native interface but there is no evidence it is consumed anywhere downstream (no normalizer reads quoteToken, no unified type maps it). This is safe as a type-accuracy fix (making the interface match the real API shape), but it does not surface the data to SDK users.
2. No test coverage for the new field. Acceptable for a raw interface addition, but if the intent (per issue Response drift: hyperliquid — outcomes[].quoteToken field present in live API but missing from TypeScript interface #555) is to expose quote currency to users, additional normalizer + type + SDK work is needed.

PMXT Pipeline Check

• Field propagation: N/A (raw interface only, not a unified field)
• OpenAPI sync: OK (no BaseExchange.ts change)
• Type safety: OK

Semver Impact

patch -- additive raw type field, no behavioral change

Risk

• If the Hyperliquid API does not always include quoteToken on every outcome, this should be quoteToken?: string (optional). The PR makes it required. Verify against real API responses.