Change knowledge_products string columns from varchar to text

Avoids 'value too long for character varying(100)' errors when importing
product catalog with long feature descriptions and URLs.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

drizzle/schema.ts

@@ -304,12 +304,12 @@ export const knowledgeSuggestions = chatbotSchema.table("knowledge_suggestions",
  */
 export const knowledgeProducts = chatbotSchema.table("knowledge_products", {
   id:           serial("id").primaryKey(),
-  model:        varchar("model", { length: 100 }).notNull(),
+  model:        text("model").notNull(),
   description:  text("description"),
   categories:   text("categories"),
-  collection:   varchar("collection", { length: 100 }),
-  price:        varchar("price", { length: 50 }),
-  availability: varchar("availability", { length: 50 }),
+  collection:   text("collection"),
+  price:        text("price"),
+  availability: text("availability"),
   features:     text("features"),
   dimensions:   text("dimensions"),
   imageUrl:     text("image_url"),