feat(web): service-worker notifications and composer/scroll UX fixes

- register notifications service worker and handle click-to-open chat/message

- route realtime notifications through service worker with fallback

- support ?chat=&message= deep-link navigation in chats page

- enforce 1s minimum voice message length

- lift scroll-to-bottom button to avoid overlap with composer action

web/src/pages/ChatsPage.tsx

@@ -52,6 +52,30 @@ export function ChatsPage() {
     }
   }, [activeChatId, loadMessages]);
 
+  useEffect(() => {
+    const applyNotificationNavigation = () => {
+      const url = new URL(window.location.href);
+      const chatParam = url.searchParams.get("chat");
+      const messageParam = url.searchParams.get("message");
+      const chatId = Number(chatParam);
+      const messageId = Number(messageParam);
+      if (!Number.isFinite(chatId) || chatId <= 0) {
+        return;
+      }
+      setActiveChatId(chatId);
+      if (Number.isFinite(messageId) && messageId > 0) {
+        setFocusedMessage(chatId, messageId);
+      }
+      url.searchParams.delete("chat");
+      url.searchParams.delete("message");
+      window.history.replaceState({}, "", url.toString());
+    };
+
+    applyNotificationNavigation();
+    window.addEventListener("popstate", applyNotificationNavigation);
+    return () => window.removeEventListener("popstate", applyNotificationNavigation);
+  }, [setActiveChatId, setFocusedMessage]);
+
   useEffect(() => {
     if (!searchOpen) {
       return;