Implement the Ollama DELETE /api/delete endpoint for removing models
from the server.
- Add DeleteRequest type with model field in src/types/delete.rs
- Add OllamaClient::delete() async method in src/lib.rs
- Register delete module in src/types/mod.rs
- Add usage example in examples/delete.rs
Replaced unwrap() with ? operator so serialization errors propagate
as OllamaError::ResponseParseError instead of panicking. This is
safer for a library API where callers should decide how to handle
errors.
