Add request examples to OpenAPI spec (docs/openapi.yaml)

[willamhou]

Description

The OpenAPI spec at docs/openapi.yaml defines the API schema but lacks request/response examples. Adding examples makes the interactive docs page much more useful.

What to Add

Add example fields to these endpoints:

• POST /api/context/load — URL input, batch input, query input
• POST /api/context/save — save with tags
• POST /api/parse — PDF parsing

Where to Look

• docs/openapi.yaml — the spec file
• docs/API.md — has curl examples you can reference

Difficulty

Beginner — YAML editing, no code changes.