feat(docs): document Goal Runs API

[Si40Code]

Summary

• sync the canonical CALL-E Developer API OpenAPI 0.6 contract from s-eleven-mono
• add the Goal Runs guide, navigation, API Reference routes, crawler/LLM artifacts, and cross-links
• document Goal discovery, run creation, polling, errors, idempotency, and the upcoming SDK surface
• correct the Goal Run idempotency wording to use the 0.6 top-level phone field

Why

The monorepo cleanup removes the historical Zudoku snapshot. Goal Runs landed in the canonical Developer API after the standalone docs repository was created, so the public source of truth must receive that content before the old snapshot is removed.

Impact

After this PR is merged, docs.heycall-e.com will publish the Goal Runs guide and Goals/Goal Runs API Reference through the existing OSS deployment workflow. Existing Calls, Webhooks, and stable 0.2 SDK documentation remain compatible.

Validation

• pnpm run validate
• TypeScript typecheck and Zudoku production build
• static dist, sitemap, llms.txt, llms-full.txt, and OpenAPI verification
• 11 OSS deployment tests
• 15 Playwright tests
• canonical and public OpenAPI SHA-256 snapshots match

Rollout dependency

Merge this PR before the companion s-eleven-mono cleanup MR !108, which removes services/seleven-mcp/sdks/docs-site. Merging this PR triggers the repository's normal production OSS deployment; this PR does not merge or deploy itself.