Remove claude-3-7-sonnet-20250219 from LLM model definitions ahead of
Anthropic's API retirement on February 19, 2026.
Changes:
- Remove CLAUDE_3_7_SONNET enum member from LlmModel
- Remove corresponding ModelMetadata entry
- Remove from StagehandRecommendedLlmModel enum
- Update Stagehand block defaults from CLAUDE_3_7_SONNET to GPT41
Note: Agent JSON files retain the model reference as they are
auto-generated and will be updated separately.