feat: realtime sync, settings UX and chat list improvements

- add chat_updated realtime event and dynamic chat subscriptions

- auto-join invite links in web app

- implement Telegram-like settings panel (general/notifications/privacy)

- add browser notification preferences and keyboard send mode

- improve chat list with last message preview/time and online badge

- rework chat members UI with context actions and role crowns

web/src/components/MessageComposer.tsx

@@ -3,6 +3,7 @@ import { attachFile, requestUploadUrl, sendMessageWithClientId, uploadToPresigne
 import { useAuthStore } from "../store/authStore";
 import { useChatStore } from "../store/chatStore";
 import { buildWsUrl } from "../utils/ws";
+import { getAppPreferences } from "../utils/preferences";
 
 type RecordingState = "idle" | "recording" | "locked";
 
@@ -149,7 +150,19 @@ export function MessageComposer() {
   }
 
   function onComposerKeyDown(event: KeyboardEvent<HTMLTextAreaElement>) {
-    if (event.key === "Enter" && !event.shiftKey) {
+    if (event.key !== "Enter") {
+      return;
+    }
+    const prefs = getAppPreferences();
+    const sendWithCtrlEnter = prefs.sendMode === "ctrl_enter";
+    if (sendWithCtrlEnter) {
+      if (event.ctrlKey) {
+        event.preventDefault();
+        void handleSend();
+      }
+      return;
+    }
+    if (!event.shiftKey) {
       event.preventDefault();
       void handleSend();
     }