feat: add generic structured output example schema

[dutifulbob]

Summary

Adds a context-agnostic example schema for localagent structured output.
The schema is generic binary classification, so localagent can show a concrete schema without baking in clawd, Scoop, or local-model workflow assumptions.

What Changed

• Added examples/schemas/binary-classifier.schema.json.
• Included examples/** in npm package files.
• Updated README and structured-output docs to use the generic example.
• Added a test that loads and checks the example schema shape.

Testing

• npm run check
• Live localagent smoke using examples/schemas/binary-classifier.schema.json and jq assertion passed.

Risks

Low. The structured-output runtime is unchanged; this only adds a generic example artifact and docs.

[dutifulbob]

Final report:

• Added examples/schemas/binary-classifier.schema.json as a context-agnostic structured-output example.
• Updated README/docs to reference the generic example.
• Included examples/** in package files.
• Added a test that loads and verifies the example schema.

Validation:

• npm run check passed locally.
• Live localagent smoke with the generic schema passed.
• GitHub Actions ci / test passed.