Update default model to gemini-3-flash-preview

Author: aliroberts

weco/constants.py

@@ -11,4 +11,4 @@
 SUPPORTED_FILE_EXTENSIONS = [".md", ".txt", ".rst"]
 
 # Default models for each provider in order of preference
-DEFAULT_MODELS = [("gemini", "gemini-3.1-pro-preview"), ("openai", "o4-mini"), ("anthropic", "claude-opus-4-5")]
+DEFAULT_MODELS = [("gemini", "gemini-3-flash-preview"), ("openai", "o4-mini"), ("anthropic", "claude-opus-4-5")]