feat(sdk): add outcome market reads

[sumfxn]

What

Track 2 of docs/roadmap.md. Adds experimental read-only outcome market support to the SDK:

• kit.listOutcomeMarkets()
• kit.getOutcomeMarket({ outcome })
• kit.getOutcomeBook({ outcome, side, nSigFigs? })
• kit.getOutcomeMids()
• exported outcome helpers/types for encoded #<encoding> side coins and asset ids
• InfoClient.outcomeMeta() with runtime validation

Safety

• Read-only only: no outcome order placement, cancel, or write path.
• Outcome support is documented as experimental.
• Docs do not claim USDH settlement/denomination beyond exposing current Hyperliquid outcome metadata/books.
• Outcome ids are clamped so encoded coin ids and asset ids remain safe JS integers.
• Malformed outcomeMeta, malformed questions, malformed side specs, invalid sides, unsafe ids, and invalid books reject with typed SDK errors.

Tests

Local after rebasing on #52:

• pnpm install --frozen-lockfile --ignore-scripts
• pnpm lint
• pnpm build
• pnpm typecheck
• pnpm test
• git diff --check
• pnpm changeset status --since=origin/main
  • SDK minor
  • widget patch
  • no major releases

Live read-only probes:

• mainnet outcomeMeta() validates
• testnet outcomeMeta() validates
• mainnet/testnet getOutcomeBook() returns valid L2 book shapes
• getOutcomeMids() returns only #... outcome keys
• invalid outcome ids/sides reject before transport
• nonexistent outcome books reject as NetworkError

Release

No npm release from this PR. The release workflow is gated behind RELEASES_ENABLED == 'true', and the generated release output still needs manual audit before any publish.