feat(09-01): add classification column to setupItems with service layer and tests

- Add classification text column (default 'base') to setupItems schema
- Add classificationSchema and updateClassificationSchema Zod validators
- Add UpdateClassification type inferred from Zod schema
- Implement updateItemClassification service function
- Modify getSetupWithItems to return classification field
- Modify syncSetupItems to preserve classifications across re-sync
- Add tests for classification CRUD, preservation, and cross-setup independence
- Generate and apply Drizzle migration

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

src/db/schema.ts

@@ -86,6 +86,7 @@ export const setupItems = sqliteTable("setup_items", {
 	itemId: integer("item_id")
 		.notNull()
 		.references(() => items.id, { onDelete: "cascade" }),
+	classification: text("classification").notNull().default("base"),
 });
 
 export const settings = sqliteTable("settings", {