fix(client): contact-request endpoint path + search screen polish

1. Contact requests silently 404'd
   fetchContactRequests hit /api/relay/contacts, but the server mounts
   the whole /relay/* group at root (no /api prefix). Result: every
   poll returned 404, the catch swallowed it, and the notifications
   tab stayed empty even after the user sent themselves a CONTACT_
   REQUEST on-chain. Fixed the client path to /relay/contacts — same
   pattern as sendEnvelope / fetchInbox in the v1.0.x relay cleanup.

2. Search screen was half-finished
   SearchBar used a dual-state hack (idle-centered Text overlaid with
   an invisible TextInput) that broke focus + alignment on Android and
   sometimes ate taps. Rewrote as a plain single-row pill: icon +
   TextInput + optional clear button. Fewer moving parts, predictable
   focus, proper placeholder styling.

   new-contact.tsx cleaned up:
   - Title "New chat" → "Поиск" (matches the NavBar tab label and the
     rest of the Russian UI).
   - All labels localised: "Accept/Decline", "Intro", "Anti-spam fee",
     fee-tier names, error messages, final CTA.
   - Proper empty-state hint when query is empty (icon + headline +
     explanation of @username / hex / DC prefix) instead of just a
     floating helper text.
   - Search button hidden until user types something — the empty-
     state stands alone, no dead grey button under it.
   - onClear handler on SearchBar resets the resolved profile too.

   requests.tsx localised: title, empty-state, Accept/Decline button
   copy, confirmation Alert text.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

client-app/app/(app)/new-contact.tsx

@@ -27,9 +27,9 @@ import { SearchBar } from '@/components/SearchBar';
 
 const MIN_CONTACT_FEE = 5000;
 const FEE_TIERS = [
-  { value: 5_000,  label: 'Min'      },
-  { value: 10_000, label: 'Standard' },
-  { value: 50_000, label: 'Priority' },
+  { value: 5_000,  label: 'Базовая'    },
+  { value: 10_000, label: 'Стандарт'   },
+  { value: 50_000, label: 'Приоритет'  },
 ];
 
 interface Resolved {
@@ -61,7 +61,7 @@ export default function NewContactScreen() {
       if (q.startsWith('@') || (!q.match(/^[0-9a-f]{64}$/i) && !q.startsWith('DC'))) {
         const name = q.replace('@', '');
         const addr = await resolveUsername(settings.contractId, name);
-        if (!addr) { setError(`@${name} is not registered on this chain`); return; }
+        if (!addr) { setError(`@${name} не зарегистрирован в этой сети`); return; }
         address = addr;
       }
       const identity = await getIdentity(address);
@@ -71,7 +71,7 @@ export default function NewContactScreen() {
         x25519:   identity?.x25519_pub || undefined,
       });
     } catch (e: any) {
-      setError(e?.message ?? 'Lookup failed');
+      setError(e?.message ?? 'Не удалось найти пользователя');
     } finally {
       setSearching(false);
     }
@@ -80,7 +80,7 @@ export default function NewContactScreen() {
   async function sendRequest() {
     if (!resolved || !keyFile) return;
     if (balance < fee + 1000) {
-      Alert.alert('Insufficient balance', `Need ${formatAmount(fee + 1000)} (fee + network).`);
+      Alert.alert('Недостаточно средств', `Нужно ${formatAmount(fee + 1000)} (плата + сетевая комиссия).`);
       return;
     }
     setSending(true); setError(null);
@@ -94,8 +94,8 @@ export default function NewContactScreen() {
       });
       await submitTx(tx);
       Alert.alert(
-        'Request sent',
-        `A contact request has been sent to ${resolved.nickname ? '@' + resolved.nickname : shortAddr(resolved.address)}.`,
+        'Запрос отправлен',
+        `Запрос на общение отправлен ${resolved.nickname ? '@' + resolved.nickname : shortAddr(resolved.address)}.`,
         [{ text: 'OK', onPress: () => router.back() }],
       );
     } catch (e: any) {
@@ -112,7 +112,7 @@ export default function NewContactScreen() {
   return (
     <View style={{ flex: 1, backgroundColor: '#000000', paddingTop: insets.top }}>
       <Header
-        title="New chat"
+        title="Поиск"
         divider={false}
         left={<IconButton icon="chevron-back" size={36} onPress={() => router.back()} />}
       />
@@ -121,33 +121,56 @@ export default function NewContactScreen() {
         keyboardShouldPersistTaps="handled"
         showsVerticalScrollIndicator={false}
       >
-        <Text style={{ color: '#8b8b8b', fontSize: 13, lineHeight: 19, marginBottom: 14 }}>
-          Enter a <Text style={{ color: '#ffffff', fontWeight: '600' }}>@username</Text>, a
-          hex pubkey or a <Text style={{ color: '#ffffff', fontWeight: '600' }}>DC…</Text> address.
-        </Text>
-
         <SearchBar
           value={query}
           onChangeText={setQuery}
-          placeholder="@alice or hex / DC address"
+          placeholder="@alice, hex pubkey или DC-адрес"
           onSubmitEditing={search}
+          autoFocus
+          onClear={() => { setResolved(null); setError(null); }}
         />
 
-        <Pressable
-          onPress={search}
-          disabled={searching || !query.trim()}
-          style={({ pressed }) => ({
-            flexDirection: 'row', alignItems: 'center', justifyContent: 'center',
-            paddingVertical: 11, borderRadius: 999, marginTop: 12,
-            backgroundColor: !query.trim() || searching ? '#1a1a1a' : pressed ? '#1a8cd8' : '#1d9bf0',
-          })}
-        >
-          {searching ? (
-            <ActivityIndicator color="#ffffff" size="small" />
-          ) : (
-            <Text style={{ color: '#ffffff', fontWeight: '700', fontSize: 14 }}>Search</Text>
-          )}
-        </Pressable>
+        {query.trim().length > 0 && (
+          <Pressable
+            onPress={search}
+            disabled={searching}
+            style={({ pressed }) => ({
+              flexDirection: 'row', alignItems: 'center', justifyContent: 'center',
+              paddingVertical: 11, borderRadius: 999, marginTop: 12,
+              backgroundColor: searching ? '#1a1a1a' : pressed ? '#1a8cd8' : '#1d9bf0',
+            })}
+          >
+            {searching ? (
+              <ActivityIndicator color="#ffffff" size="small" />
+            ) : (
+              <Text style={{ color: '#ffffff', fontWeight: '700', fontSize: 14 }}>Найти</Text>
+            )}
+          </Pressable>
+        )}
+
+        {/* Empty-state hint — показываем когда ничего не введено и нет результата */}
+        {query.trim().length === 0 && !resolved && (
+          <View style={{ marginTop: 28, alignItems: 'center', paddingHorizontal: 16 }}>
+            <View
+              style={{
+                width: 56, height: 56, borderRadius: 16,
+                backgroundColor: '#0a0a0a',
+                borderWidth: 1, borderColor: '#1f1f1f',
+                alignItems: 'center', justifyContent: 'center',
+                marginBottom: 12,
+              }}
+            >
+              <Ionicons name="person-add-outline" size={24} color="#6a6a6a" />
+            </View>
+            <Text style={{ color: '#ffffff', fontSize: 15, fontWeight: '700', marginBottom: 6 }}>
+              Найдите собеседника
+            </Text>
+            <Text style={{ color: '#8b8b8b', fontSize: 13, textAlign: 'center', lineHeight: 19 }}>
+              Введите <Text style={{ color: '#ffffff', fontWeight: '600' }}>@username</Text>,
+              если человек зарегистрировал ник, либо полный hex pubkey или <Text style={{ color: '#ffffff', fontWeight: '600' }}>DC…</Text> адрес.
+            </Text>
+          </View>
+        )}
 
         {error && (
           <View style={{
@@ -195,7 +218,7 @@ export default function NewContactScreen() {
                       color: resolved.x25519 ? '#3ba55d' : '#f0b35a',
                       fontSize: 11, fontWeight: '500',
                     }}>
-                      {resolved.x25519 ? 'E2E-ready' : 'Key not published yet'}
+                      {resolved.x25519 ? 'E2E готов' : 'Ключ ещё не опубликован'}
                     </Text>
                   </View>
                 </View>
@@ -204,12 +227,12 @@ export default function NewContactScreen() {
 
             {/* Intro */}
             <Text style={{ color: '#8b8b8b', fontSize: 12, marginTop: 18, marginBottom: 6 }}>
-              Intro (optional, plaintext on-chain)
+              Сообщение (опционально, видно в открытом виде на chain)
             </Text>
             <TextInput
               value={intro}
               onChangeText={setIntro}
-              placeholder="Hey, it's Jordan from the conference"
+              placeholder="Привет! Это Влад со встречи в среду"
               placeholderTextColor="#5a5a5a"
               multiline
               maxLength={140}
@@ -227,7 +250,7 @@ export default function NewContactScreen() {
 
             {/* Fee tier */}
             <Text style={{ color: '#8b8b8b', fontSize: 12, marginTop: 14, marginBottom: 6 }}>
-              Anti-spam fee (goes to recipient)
+              Плата за запрос (уходит получателю, anti-spam)
             </Text>
             <View style={{ flexDirection: 'row', gap: 8 }}>
               {FEE_TIERS.map(t => {
@@ -276,7 +299,7 @@ export default function NewContactScreen() {
                 <ActivityIndicator color="#ffffff" size="small" />
               ) : (
                 <Text style={{ color: '#ffffff', fontWeight: '700', fontSize: 14 }}>
-                  Send request · {formatAmount(fee + 1000)}
+                  Отправить запрос · {formatAmount(fee + 1000)}
                 </Text>
               )}
             </Pressable>