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>

drizzle/meta/_journal.json

@@ -22,6 +22,13 @@
       "when": 1773666521689,
       "tag": "0002_broken_roughhouse",
       "breakpoints": true
+    },
+    {
+      "idx": 3,
+      "version": "6",
+      "when": 1773670263013,
+      "tag": "0003_misty_mongu",
+      "breakpoints": true
     }
   ]
 }