test(02-01): add failing tests for thread service

- Add threads and threadCandidates tables to Drizzle schema
- Add Zod schemas for thread/candidate/resolve validation
- Add Thread/ThreadCandidate types to shared types
- Update test helper with threads and thread_candidates tables
- Write comprehensive failing tests for thread service

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

src/shared/types.ts

@@ -4,15 +4,27 @@ import type {
   updateItemSchema,
   createCategorySchema,
   updateCategorySchema,
+  createThreadSchema,
+  updateThreadSchema,
+  createCandidateSchema,
+  updateCandidateSchema,
+  resolveThreadSchema,
 } from "./schemas.ts";
-import type { items, categories } from "../db/schema.ts";
+import type { items, categories, threads, threadCandidates } from "../db/schema.ts";
 
 // Types inferred from Zod schemas
 export type CreateItem = z.infer<typeof createItemSchema>;
 export type UpdateItem = z.infer<typeof updateItemSchema>;
 export type CreateCategory = z.infer<typeof createCategorySchema>;
 export type UpdateCategory = z.infer<typeof updateCategorySchema>;
+export type CreateThread = z.infer<typeof createThreadSchema>;
+export type UpdateThread = z.infer<typeof updateThreadSchema>;
+export type CreateCandidate = z.infer<typeof createCandidateSchema>;
+export type UpdateCandidate = z.infer<typeof updateCandidateSchema>;
+export type ResolveThread = z.infer<typeof resolveThreadSchema>;
 
 // Types inferred from Drizzle schema
 export type Item = typeof items.$inferSelect;
 export type Category = typeof categories.$inferSelect;
+export type Thread = typeof threads.$inferSelect;
+export type ThreadCandidate = typeof threadCandidates.$inferSelect;