feat: announce on Discourse support forum (#17)

## Summary

- Adds `announceOnDiscourse` module to post announcements to the NHCarrigan Discourse support forum (category 16), tagged by announcement type
- Adds `chunkContent` utility to split long announcements at paragraph/line boundaries for Discord (2000 chars), Reddit (40,000 chars), and Discourse (32,000 chars); Reddit overflows chain as nested replies, Discord as sequential messages, Discourse as sequential replies
- Refactors the announcement route to run all platforms concurrently via `Promise.allSettled`, ensuring a failure on any one platform never blocks the others, with all results reported back
- Fixes generation failure response from incorrect `201` to `500`

✨ This PR was created with love from Hikari~ 🌸

Reviewed-on: #17
Co-authored-by: Hikari <hikari@nhcarrigan.com>
Co-committed-by: Hikari <hikari@nhcarrigan.com>

server/src/modules/announceOnDiscord.ts

@@ -4,9 +4,15 @@
  * @author Naomi Carrigan
  */
 /* eslint-disable @typescript-eslint/naming-convention -- we are making raw API calls. */
+/* eslint-disable max-lines-per-function -- Chunked sending requires more logic. */
+/* eslint-disable max-statements -- Chunked sending requires more statements. */
+/* eslint-disable no-await-in-loop -- Sequential chunk posting requires awaiting each request. */
 
+import { chunkContent } from "../utils/chunkContent.js";
 import type { AnnouncementType } from "../interfaces/announcementType.js";
 
+const discordLimit = 2000;
+
 const channelIds: Record<AnnouncementType, string> = {
   community: "1386105484313886820",
   company:   "1422472775695728661",
@@ -25,6 +31,7 @@ const getAnnouncementPing = (type: AnnouncementType): string => {
 
 /**
  * Forwards an announcement to our Discord server.
+ * Sends content in sequential messages if it exceeds the 2000 character limit.
  * @param title - The title of the announcement.
  * @param content - The main body of the announcement.
  * @param type - Whether the announcement is for a product or community.
@@ -35,12 +42,23 @@ export const announceOnDiscord = async(
   content: string,
   type: AnnouncementType,
 ): Promise<string> => {
+  const channelId = channelIds[type];
+  const ping = getAnnouncementPing(type);
+  const firstMessagePrefix = `# ${title}\n\n`;
+  const firstMessageSuffix = `\n-# ${ping}`;
+  const firstChunkLimit
+    = discordLimit - firstMessagePrefix.length - firstMessageSuffix.length;
+
+  const chunks = chunkContent(content, firstChunkLimit);
+  const firstChunk = chunks[0] ?? "";
+  const remainingChunks = chunks.slice(1);
+
   const messageRequest = await fetch(
-    `https://discord.com/api/v10/channels/${channelIds[type]}/messages`,
+    `https://discord.com/api/v10/channels/${channelId}/messages`,
     {
       body: JSON.stringify({
         allowed_mentions: { parse: [ "users", "roles" ] },
-        content:          `# ${title}\n\n${content}\n-# ${getAnnouncementPing(type)}`,
+        content:          `${firstMessagePrefix}${firstChunk}${firstMessageSuffix}`,
       }),
       headers: {
         "Authorization": `Bot ${process.env.DISCORD_TOKEN ?? ""}`,
@@ -49,16 +67,19 @@ export const announceOnDiscord = async(
       method: "POST",
     },
   );
+
   if (messageRequest.status !== 200) {
     return `Failed to send message to Discord. Status: ${messageRequest.status.toString()} ${messageRequest.statusText}`;
   }
+
   // eslint-disable-next-line @typescript-eslint/consistent-type-assertions -- fetch does not accept generics.
   const message = await messageRequest.json() as { id?: string };
   if (message.id === undefined) {
     return `Failed to parse message ID, cannot crosspost. ${JSON.stringify(message)}`;
   }
+
   const crosspostRequest = await fetch(
-    `https://discord.com/api/v10/channels/${channelIds[type]}/messages/${message.id}/crosspost`,
+    `https://discord.com/api/v10/channels/${channelId}/messages/${message.id}/crosspost`,
     {
       headers: {
         "Authorization": `Bot ${process.env.DISCORD_TOKEN ?? ""}`,
@@ -67,8 +88,30 @@ export const announceOnDiscord = async(
       method: "POST",
     },
   );
+
   if (!crosspostRequest.ok) {
     return `Failed to crosspost message to Discord. Status: ${crosspostRequest.status.toString()} ${crosspostRequest.statusText}`;
   }
+
+  for (const chunk of remainingChunks) {
+    const chunkRequest = await fetch(
+      `https://discord.com/api/v10/channels/${channelId}/messages`,
+      {
+        body: JSON.stringify({
+          content: chunk,
+        }),
+        headers: {
+          "Authorization": `Bot ${process.env.DISCORD_TOKEN ?? ""}`,
+          "Content-Type":  "application/json",
+        },
+        method: "POST",
+      },
+    );
+
+    if (!chunkRequest.ok) {
+      return `Failed to send continuation chunk to Discord. Status: ${chunkRequest.status.toString()} ${chunkRequest.statusText}`;
+    }
+  }
+
   return "Successfully sent and published message to Discord.";
 };