feat(sdk): build validation, unit tests, and npm publish prep

[Depo-dev]

Summary

The SDK has no tests and npm run build has not been validated end-to-end. This issue covers test coverage, build output verification, and npm publish readiness.

Acceptance Criteria

Build

• npm run build produces valid dist/index.cjs, dist/index.mjs, dist/index.d.ts
• CJS and ESM imports both work in a Node.js smoke test script

Tests (Vitest)

• Unit test: queryEvents serialises params correctly and calls the right URL
• Unit test: getEventById returns parsed event on 200
• Unit test: 404 response throws TridentError with NOT_FOUND code
• Unit test: 401 response throws TridentError with UNAUTHORIZED code
• Mock fetch / WebSocket in tests (no real network calls)

npm publish prep

• package.json name: @trident-indexer/sdk, version 0.1.0
• "files" field: ["dist"]
• README.md with install + usage example
• npm pack dry run succeeds

Files

sdk/typescript/src/, sdk/typescript/tests/ (new), sdk/typescript/package.json