feat(sdk): add yaml-aligned eval authoring helpers

[christso]

Summary

TypeScript .eval.ts suites can now use @agentv/sdk to author YAML-aligned eval definitions with camelCase ergonomics while still loading through AgentV's canonical YAML parser/runtime path. This keeps @agentv/core as the runner source of truth and preserves snake_case serialization with assertions as the durable field.

What Changed

• Added defineEval(), evalSuite(), toEvalYamlObject(), and serializeEvalYaml() to @agentv/sdk, along with typed suite, test, execution, and workspace authoring interfaces.
• Added a whitelist lowerer that converts known AgentV wire keys such as expectedOutput, inputFiles, lifecycle hook names, and execution aliases without rewriting opaque user payload keys.
• Taught the TypeScript eval loader to detect SDK-authored suites and materialize them by lowering into the existing YAML parser path instead of widening the core runner API.
• Added SDK unit coverage, loader fixtures/tests, and a runnable examples/features/sdk-eval-authoring/ dogfood example.
• Updated SDK docs and README guidance to point new eval authoring toward @agentv/sdk instead of the deprecated @agentv/eval surface.

Testing

• git diff --check
• bun --filter @agentv/sdk test
• bun test packages/core/test/evaluation/loaders/ts-eval-loader.test.ts
• bun --filter @agentv/sdk build
• bun --filter @agentv/core build
• bun apps/cli/src/cli.ts eval examples/features/sdk-eval-authoring/evals/greeting.eval.ts --output <tmp>
• bun run validate:examples
• bun run typecheck
• bun run lint

---

[cloudflare-workers-and-pages]

Deploying agentv with    Cloudflare Pages

Latest commit:	dc7e0ae
Status:	✅  Deploy successful!
Preview URL:	https://e750688a.agentv.pages.dev
Branch Preview URL:	https://feat-sdk-yaml-helpers.agentv.pages.dev

View logs