v4: a moderator's or an admin's @everyone in the chat notifies every user — there was no way to reach everyone at once. The new chat:everyone permission, held by moderators and admins, lets a chat message saying @everyone notify every user but its author and those reading the chat, through notifyEveryone, after notifyMentions, so a user also named is told once, by name; the notification is a user_mentioned with everyone set, which the notifications page and the digest word as "mentioned everyone in the chat". chat_messages.mentions_everyone, sent as ChatMessage.mentionsEveryone, is set from the author's role each time the body is written, so a user's @everyone reaches no one, a moderator's edit of a user's message can't make it reach everyone, and a demoted author's next edit loses it. Only an edit that adds @everyone notifies, so fixing an announcement's typo reaches no one new. The client highlights and chimes by the flag, never by the text; Markdown shows @everyone as a mention only in a flagged message, and never links it to a profile. The chat composer offers @everyone first to those who may say it. No account may be named everyone, in any case: migration 0023 adds the column, flags the moderators' and admins' past @everyone messages, renames a user named everyone to everyone_N and drops an alias everyone. 265 backend tests and 681 frontend tests pass, and deno check, tsc, eslint, doc:lint and i18n:compile --strict are clean; checked in screenshots of the chat at 1280 and 390px, with a moderator's and a user's @everyone and the suggestions open.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

src/test/hooks/editor/useMentionAutocomplete.test.tsx

@@ -29,9 +29,9 @@ describe("useMentionAutocomplete", () => {
     { id: "3", username: "albert", avatarMime: null },
   ];
 
-  function setup() {
+  function setup(everyone = false) {
     const replace = vi.fn();
-    const hook = renderHook(() => useMentionAutocomplete(replace));
+    const hook = renderHook(() => useMentionAutocomplete(replace, everyone));
     const type = async (value: string, cursor = value.length) => {
       act(() => hook.result.current.syncMention(value, cursor, true));
       await act(() => vi.advanceTimersByTimeAsync(200));
@@ -56,6 +56,21 @@ describe("useMentionAutocomplete", () => {
     );
   });
 
+  test("offers @everyone first, only when allowed", async () => {
+    route("GET /api/users", () => [users[0]]);
+    const allowed = setup(true);
+    await allowed.type("@E");
+    expect(allowed.hook.result.current.mentionResults.map((u) => u.username))
+      .toEqual(["everyone", "alice"]);
+    await allowed.type("@al");
+    expect(allowed.hook.result.current.mentionResults.map((u) => u.username))
+      .toEqual(["alice"]);
+    const denied = setup();
+    await denied.type("@e");
+    expect(denied.hook.result.current.mentionResults.map((u) => u.username))
+      .toEqual(["alice"]);
+  });
+
   test("debounces keystrokes into one lookup", async () => {
     route("GET /api/users", () => users);
     const { hook } = setup();