claude-3-sonnet-20240229 was retired 2025-07-21, so the wrapper's
default model and every copy-paste doc example would fail at
generate() time out of the box. Switch to claude-sonnet-4-6
everywhere (wrapper default, __init__ docstring, docs guide, tests).
Also cleans up leftover docstring typos/spacing from the previous
review pass and adds unavailable-path test coverage for
generate_structured()/generate_typed() to match generate(), clearing
ANTHROPIC_API_KEY in those tests so they don't flake on a runner that
has a real key set.
KaifAhmad1
9d98eedaa1