chore: simplify error formatting and clean up model assignment logic

### CHANGES
- Remove redundant fmt.Sprintf calls from error formatting logic
- Simplify model assignment to always use normalized model names
- Remove unused variadic parameter from the VendorsManager Clear method

internal/cli/flags.go

@@ -283,30 +283,30 @@ func assignWithConversion(targetField, sourceField reflect.Value) error {
 				return nil
 			}
 		}
-		return fmt.Errorf("%s", fmt.Sprintf(i18n.T("cannot_convert_string"), str, targetField.Kind()))
+		return fmt.Errorf(i18n.T("cannot_convert_string"), str, targetField.Kind())
 	}
 
-	return fmt.Errorf("%s", fmt.Sprintf(i18n.T("unsupported_conversion"), sourceField.Kind(), targetField.Kind()))
+	return fmt.Errorf(i18n.T("unsupported_conversion"), sourceField.Kind(), targetField.Kind())
 }
 
 func loadYAMLConfig(configPath string) (*Flags, error) {
 	absPath, err := util.GetAbsolutePath(configPath)
 	if err != nil {
-		return nil, fmt.Errorf("%s", fmt.Sprintf(i18n.T("invalid_config_path"), err))
+		return nil, fmt.Errorf(i18n.T("invalid_config_path"), err)
 	}
 
 	data, err := os.ReadFile(absPath)
 	if err != nil {
 		if os.IsNotExist(err) {
-			return nil, fmt.Errorf("%s", fmt.Sprintf(i18n.T("config_file_not_found"), absPath))
+			return nil, fmt.Errorf(i18n.T("config_file_not_found"), absPath)
 		}
-		return nil, fmt.Errorf("%s", fmt.Sprintf(i18n.T("error_reading_config_file"), err))
+		return nil, fmt.Errorf(i18n.T("error_reading_config_file"), err)
 	}
 
 	// Use the existing Flags struct for YAML unmarshal
 	config := &Flags{}
 	if err := yaml.Unmarshal(data, config); err != nil {
-		return nil, fmt.Errorf("%s", fmt.Sprintf(i18n.T("error_parsing_config_file"), err))
+		return nil, fmt.Errorf(i18n.T("error_parsing_config_file"), err)
 	}
 
 	debuglog.Debug(debuglog.Detailed, "Config: %v\n", config)
@@ -324,7 +324,7 @@ func readStdin() (ret string, err error) {
 				sb.WriteString(line)
 				break
 			}
-			err = fmt.Errorf("%s", fmt.Sprintf(i18n.T("error_reading_piped_message"), readErr))
+			err = fmt.Errorf(i18n.T("error_reading_piped_message"), readErr)
 			return
 		} else {
 			sb.WriteString(line)
@@ -342,7 +342,7 @@ func validateImageFile(imagePath string) error {
 
 	// Check if file already exists
 	if _, err := os.Stat(imagePath); err == nil {
-		return fmt.Errorf("%s", fmt.Sprintf(i18n.T("image_file_already_exists"), imagePath))
+		return fmt.Errorf(i18n.T("image_file_already_exists"), imagePath)
 	}
 
 	// Check file extension
@@ -353,7 +353,7 @@ func validateImageFile(imagePath string) error {
 		return nil // Valid extension found
 	}
 
-	return fmt.Errorf("%s", fmt.Sprintf(i18n.T("invalid_image_file_extension"), ext))
+	return fmt.Errorf(i18n.T("invalid_image_file_extension"), ext)
 }
 
 // validateImageParameters validates image generation parameters
@@ -371,7 +371,7 @@ func validateImageParameters(imagePath, size, quality, background string, compre
 		validSizes := []string{"1024x1024", "1536x1024", "1024x1536", "auto"}
 		valid := slices.Contains(validSizes, size)
 		if !valid {
-			return fmt.Errorf("%s", fmt.Sprintf(i18n.T("invalid_image_size"), size))
+			return fmt.Errorf(i18n.T("invalid_image_size"), size)
 		}
 	}
 
@@ -380,7 +380,7 @@ func validateImageParameters(imagePath, size, quality, background string, compre
 		validQualities := []string{"low", "medium", "high", "auto"}
 		valid := slices.Contains(validQualities, quality)
 		if !valid {
-			return fmt.Errorf("%s", fmt.Sprintf(i18n.T("invalid_image_quality"), quality))
+			return fmt.Errorf(i18n.T("invalid_image_quality"), quality)
 		}
 	}
 
@@ -389,7 +389,7 @@ func validateImageParameters(imagePath, size, quality, background string, compre
 		validBackgrounds := []string{"opaque", "transparent"}
 		valid := slices.Contains(validBackgrounds, background)
 		if !valid {
-			return fmt.Errorf("%s", fmt.Sprintf(i18n.T("invalid_image_background"), background))
+			return fmt.Errorf(i18n.T("invalid_image_background"), background)
 		}
 	}
 
@@ -399,17 +399,17 @@ func validateImageParameters(imagePath, size, quality, background string, compre
 	// Validate compression (only for jpeg/webp)
 	if compression != 0 { // 0 means not set
 		if ext != ".jpg" && ext != ".jpeg" && ext != ".webp" {
-			return fmt.Errorf("%s", fmt.Sprintf(i18n.T("image_compression_jpeg_webp_only"), ext))
+			return fmt.Errorf(i18n.T("image_compression_jpeg_webp_only"), ext)
 		}
 		if compression < 0 || compression > 100 {
-			return fmt.Errorf("%s", fmt.Sprintf(i18n.T("image_compression_range_error"), compression))
+			return fmt.Errorf(i18n.T("image_compression_range_error"), compression)
 		}
 	}
 
 	// Validate background transparency (only for png/webp)
 	if background == "transparent" {
 		if ext != ".png" && ext != ".webp" {
-			return fmt.Errorf("%s", fmt.Sprintf(i18n.T("transparent_background_png_webp_only"), ext))
+			return fmt.Errorf(i18n.T("transparent_background_png_webp_only"), ext)
 		}
 	}
 

internal/core/chatter.go

@@ -53,13 +53,9 @@ func (o *Chatter) Send(request *domain.ChatRequest, opts *domain.ChatOptions) (s
 		return
 	}
 
-	if opts.Model == "" {
-		opts.Model = o.model
-	} else {
-		// Ensure opts.Model uses the normalized name from o.model if they refer to the same model
-		// This handles cases where user provides "GPT-5" but we've normalized it to "gpt-5"
-		opts.Model = o.model
-	}
+	// Always use the normalized model name from the Chatter
+	// This handles cases where user provides "GPT-5" but we've normalized it to "gpt-5"
+	opts.Model = o.model
 
 	if opts.ModelContextLength == 0 {
 		opts.ModelContextLength = o.modelContextLength

internal/plugins/ai/vendors.go

@@ -35,7 +35,7 @@ func (o *VendorsManager) AddVendors(vendors ...Vendor) {
 	}
 }
 
-func (o *VendorsManager) Clear(vendors ...Vendor) {
+func (o *VendorsManager) Clear() {
 	o.VendorsByName = map[string]Vendor{}
 	o.Vendors = []Vendor{}
 	o.Models = nil