feat: Refactor template handling and brand management

- Removed schema_json from article templates and related queries.
- Updated brand service to include website field in requests and responses.
- Simplified template wizard view by eliminating unused schema fields and related logic.
- Added tests for ark text format handling.
- Created migrations for dropping schema_json and adding website to brands.

server/internal/shared/llm/ark.go

@@ -132,31 +132,7 @@ func (c *arkClient) Generate(ctx context.Context, req GenerateRequest, onDelta f
 		},
 	}
 
-	var textFormat *responses.ResponsesText
-	if req.ResponseFormat != nil {
-		format := &responses.TextFormat{
-			Name: strings.TrimSpace(req.ResponseFormat.Name),
-		}
-		switch req.ResponseFormat.Type {
-		case ResponseFormatTypeJSONSchema:
-			format.Type = responses.TextType_json_schema
-		case ResponseFormatTypeJSONObject:
-			format.Type = responses.TextType_json_object
-		default:
-			format.Type = responses.TextType_text
-		}
-		if description := strings.TrimSpace(req.ResponseFormat.Description); description != "" {
-			format.Description = &description
-		}
-		if len(req.ResponseFormat.SchemaJSON) > 0 {
-			format.Schema = &responses.Bytes{Value: req.ResponseFormat.SchemaJSON}
-		}
-		if req.ResponseFormat.Strict {
-			strict := true
-			format.Strict = &strict
-		}
-		textFormat = &responses.ResponsesText{Format: format}
-	}
+	textFormat := buildArkTextFormat(req.ResponseFormat)
 
 	var tools []*responses.ResponsesTool
 	if req.WebSearch != nil && req.WebSearch.Enabled {
@@ -260,6 +236,38 @@ func (c *arkClient) Generate(ctx context.Context, req GenerateRequest, onDelta f
 	}, nil
 }
 
+func buildArkTextFormat(format *ResponseFormat) *responses.ResponsesText {
+	if format == nil {
+		return nil
+	}
+
+	textFormat := &responses.TextFormat{}
+	switch format.Type {
+	case ResponseFormatTypeJSONSchema:
+		textFormat.Type = responses.TextType_json_schema
+		if name := strings.TrimSpace(format.Name); name != "" {
+			textFormat.Name = name
+		}
+		if description := strings.TrimSpace(format.Description); description != "" {
+			textFormat.Description = &description
+		}
+		if len(format.SchemaJSON) > 0 {
+			textFormat.Schema = &responses.Bytes{Value: format.SchemaJSON}
+		}
+		if format.Strict {
+			strict := true
+			textFormat.Strict = &strict
+		}
+	case ResponseFormatTypeJSONObject:
+		// Ark only accepts the type discriminator for json_object.
+		textFormat.Type = responses.TextType_json_object
+	default:
+		textFormat.Type = responses.TextType_text
+	}
+
+	return &responses.ResponsesText{Format: textFormat}
+}
+
 func resolveArkReasoning(value string) *responses.ResponsesReasoning {
 	switch strings.ToLower(strings.TrimSpace(value)) {
 	case "":