Implement support for output schemas (#411)

* tweak examples

* tweak prompt

* Implement support for output schemas

* fix: add example for structured output with zod schema

* tweak

* remove redundant cast

* fix input name

* strip $schema

* hack around vendor requirement

* clarify required result output

---------

Co-authored-by: pullfrog[bot] <226033991+pullfrog[bot]@users.noreply.github.com>

package.json

@@ -36,6 +36,7 @@
     "@opencode-ai/sdk": "^1.0.143",
     "@standard-schema/spec": "1.0.0",
     "@toon-format/toon": "^1.0.0",
+    "ajv": "^8.18.0",
     "arkregex": "0.0.5",
     "arktype": "2.1.29",
     "dotenv": "^17.2.3",