feat: add gemini-3-pro-image-preview/gemini-2.5-flash-image/gemini-3.1-flash-image-preview to supported image presets

setting/model_setting/gemini.go

@@ -27,6 +27,9 @@ var defaultGeminiSettings = GeminiSettings{
 	SupportedImagineModels: []string{
 		"gemini-2.0-flash-exp-image-generation",
 		"gemini-2.0-flash-exp",
+		"gemini-3-pro-image-preview",
+		"gemini-2.5-flash-image",
+		"gemini-3.1-flash-image-preview",
 	},
 	ThinkingAdapterEnabled:                false,
 	ThinkingAdapterBudgetTokensPercentage: 0.6,