feat(11-01): PATCH /api/threads/:id/candidates/reorder route + tests

- Import reorderCandidatesSchema and reorderCandidates into threads route
- Add PATCH /:id/candidates/reorder route with Zod validation
- Returns 200 + { success: true } on active thread, 400 on resolved thread
- Add 5 route tests: success, order persists, resolved guard, empty array, missing field

src/server/routes/threads.ts

@@ -5,6 +5,7 @@ import { Hono } from "hono";
 import {
 	createCandidateSchema,
 	createThreadSchema,
+	reorderCandidatesSchema,
 	resolveThreadSchema,
 	updateCandidateSchema,
 	updateThreadSchema,
@@ -16,6 +17,7 @@ import {
 	deleteThread,
 	getAllThreads,
 	getThreadWithCandidates,
+	reorderCandidates,
 	resolveThread,
 	updateCandidate,
 	updateThread,
@@ -122,6 +124,21 @@ app.delete("/:threadId/candidates/:candidateId", async (c) => {
 	return c.json({ success: true });
 });
 
+// Candidate reorder
+
+app.patch(
+	"/:id/candidates/reorder",
+	zValidator("json", reorderCandidatesSchema),
+	(c) => {
+		const db = c.get("db");
+		const threadId = Number(c.req.param("id"));
+		const { orderedIds } = c.req.valid("json");
+		const result = reorderCandidates(db, threadId, orderedIds);
+		if (!result.success) return c.json({ error: result.error }, 400);
+		return c.json({ success: true });
+	},
+);
+
 // Resolution
 
 app.post("/:id/resolve", zValidator("json", resolveThreadSchema), (c) => {