Function infer_annotations_from_method 

pub fn infer_annotations_from_method(method: &str) -> ModuleAnnotations

Infer behavioral annotations from an HTTP method.

Mapping:

• GET -> readonly=true, cacheable=true
• HEAD -> readonly=true (inspection-only, no body)
• OPTIONS -> readonly=true (metadata query, no mutation)
• DELETE -> destructive=true
• PUT -> idempotent=true
• POST -> default (all false; creates resources, not idempotent by spec)
• PATCH -> default (partial update, not standardly idempotent)