fix(ai): return validated elements from array output parseCompleteOutput

[AVtheking]

Background

When using generateText with output: Output.array(...), the parseCompleteOutput method validated each element with safeValidateTypes but discarded validationResult.value, returning the raw parsed JSON (outerValue.elements) instead. This silently dropped any schema transforms (.transform()), coercions (.coerce), and defaults (.default()), causing the TypeScript return type Array<ELEMENT> to be incorrect at runtime.

Summary

• Collect validationResult.value during the validation loop and return the validated array instead of outerValue.elements
• Remove the unsafe as Array<ELEMENT> type assertion
• Add regression tests including one with a .transform() schema that proves returned values come from validation, not raw JSON

Manual Verification

Ran the output.test.ts test suite — all 62 tests pass, including the new transform test which would fail on the old code (it would return { content: "hello" } instead of { content: "hello", extra: true }).

Checklist

• All commits are signed (PRs with unsigned commits cannot be merged)
• Tests have been added / updated (for bug fixes / features)
• Documentation has been added / updated (for bug fixes / features)
• A patch changeset for relevant packages has been added (for bug fixes / features - run pnpm changeset in the project root)
• I have reviewed this pull request (self-review)

Related Issues

Fixes #15708