feat: add route to get voters for an answer

src/api/routes/channels/#channel_id/polls/#poll_id/answers/#answer_id.ts

@@ -0,0 +1,43 @@
+/*
+  Spacebar: A FOSS re-implementation and extension of the Discord.com backend.
+  Copyright (C) 2026 Spacebar and Spacebar Contributors
+
+  This program is free software: you can redistribute it and/or modify
+  it under the terms of the GNU Affero General Public License as published
+  by the Free Software Foundation, either version 3 of the License, or
+  (at your option) any later version.
+
+  This program is distributed in the hope that it will be useful,
+  but WITHOUT ANY WARRANTY; without even the implied warranty of
+  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+  GNU Affero General Public License for more details.
+
+  You should have received a copy of the GNU Affero General Public License
+  along with this program.  If not, see <https://www.gnu.org/licenses/>.
+*/
+
+import { Request, Response, Router } from "express";
+import { route } from "@spacebar/api/util/handlers/route";
+import { Message, User } from "#database";
+import { DiscordApiErrors } from "#util";
+import { PollAnswerCount } from "#schemas";
+import { In } from "typeorm";
+
+const router: Router = Router({ mergeParams: true });
+
+router.get("/", route({ permission: "VIEW_CHANNEL" }), async (req: Request, res: Response) => {
+    const { poll_id, answer_id } = req.params as { [key: string]: string };
+
+    const message = await Message.findOne({ where: { id: poll_id } });
+
+    if (!message || !message.poll || !message.poll.results) {
+        throw DiscordApiErrors.UNKNOWN_MESSAGE;
+    }
+
+    const answerCount = message.poll.results.answer_counts.find((a) => a.id === answer_id) as unknown as Omit<PollAnswerCount, "me_voted"> & { voters: string[] };
+    const usersAnswered = (await User.find({ where: { id: In(answerCount.voters) } })).map((user) => user.toPublicUser());
+
+    res.send({ users: usersAnswered });
+});
+
+export default router;