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/tenant/repository/generated/models.go

@@ -31,7 +31,6 @@ type ArticleTemplate struct {
 	ShareCodeID             pgtype.Int8        `json:"share_code_id"`
 	TemplateKey             string             `json:"template_key"`
 	TemplateName            string             `json:"template_name"`
-	SchemaJson              []byte             `json:"schema_json"`
 	PromptTemplate          pgtype.Text        `json:"prompt_template"`
 	PromptVisibility        string             `json:"prompt_visibility"`
 	ProtectedPromptAssetKey pgtype.Text        `json:"protected_prompt_asset_key"`