Реализованы задачи бэклога 1-5 (1я не до конца)

codebase/backend/frontend-test-site/app/dialogs/[dialogId].tsx

@@ -1,5 +1,5 @@
 import { useQuery, useQueryClient } from "@tanstack/react-query";
-import { useLocalSearchParams } from "expo-router";
+import { useLocalSearchParams, useRouter } from "expo-router";
 import React, { useEffect, useMemo, useState } from "react";
 import { Platform, ScrollView, Text, View } from "react-native";
 import { useApp } from "../../src/app-context";
@@ -23,9 +23,11 @@ export default function ChatScreen() {
   const { dialogId } = useLocalSearchParams<{ dialogId: string }>();
   const app = useApp();
   const client = useQueryClient();
+  const router = useRouter();
   const [text, setText] = useState("");
   const [error, setError] = useState<unknown>();
   const [sending, setSending] = useState(false);
+  const [creating, setCreating] = useState(false);
   const config = useQuery({ queryKey: ["public-config"], queryFn: publicApi.config });
   const dialog = useQuery({ queryKey: ["dialog", dialogId], queryFn: () => dialogApi.get(dialogId), enabled: Boolean(dialogId) && app.authStatus === "authenticated" });
   const messages = useQuery({ queryKey: ["messages", dialogId], queryFn: () => dialogApi.messages(dialogId), enabled: Boolean(dialogId) && app.authStatus === "authenticated" });
@@ -104,6 +106,15 @@ export default function ChatScreen() {
     } catch (reason) { setError(reason); }
   };
 
+  const createDialog = async () => {
+    setCreating(true); setError(undefined);
+    try {
+      const created = await dialogApi.create(crypto.randomUUID());
+      router.replace(`/dialogs/${created.dialog_id}`);
+    } catch (reason) { setError(reason); }
+    finally { setCreating(false); }
+  };
+
   const closed = dialog.data?.status === "closed";
   return <ScrollView contentContainerStyle={styles.page}>
     <Header status={app.authStatus} realtime={app.realtimeState} onLogout={app.authStatus === "authenticated" ? () => void app.signOut() : undefined} />
@@ -122,7 +133,11 @@ export default function ChatScreen() {
       </View>)}
       {!messages.isLoading && !messages.data?.items.length && <Text style={styles.muted}>Сообщений пока нет.</Text>}
     </View>
-    {closed ? <Text style={styles.muted}>Диалог закрыт и доступен только для чтения.</Text> : <View style={styles.card}>
+    {closed ? <View style={styles.card}>
+      <Text style={styles.muted}>Диалог закрыт и доступен только для чтения.</Text>
+      <Button title={creating ? "Создание…" : "Начать новый диалог"} disabled={creating} onPress={() => void createDialog()} />
+      {error && <ErrorNotice error={error} retry={() => void createDialog()} />}
+    </View> : <View style={styles.card}>
       <Field label="Новое сообщение" multiline value={text} onChangeText={setText} />
       <View style={styles.row}>
         <Button title={sending ? "Отправка…" : "Отправить"} disabled={sending || !text.trim()} onPress={() => void sendText()} />