feat(client): Twitter-style social feed UI (Phase C of v2.0.0)

Ships the client side of the v2.0.0 feed feature. Folds client-app/
into the monorepo (was previously .gitignored as "tracked separately"
but no separate repo ever existed — for v2.0.0 the client is
first-class).

Feed screens

  app/(app)/feed.tsx — Feed tab
    - Three-way tab strip: Подписки / Для вас / В тренде backed by
      /feed/timeline, /feed/foryou, /feed/trending respectively
    - Default landing tab is "Для вас" — surfaces discovery without
      requiring the user to follow anyone first
    - FlatList with pull-to-refresh + viewability-driven view counter
      bump (posts visible ≥ 60% for ≥ 1s trigger POST /feed/post/…/view)
    - Floating blue compose button → /compose
    - Per-post liked_by_me fetched in batches of 6 after list load

  app/(app)/compose.tsx — post composer modal
    - Fullscreen, Twitter-like header (✕ left, Опубликовать right)
    - Auto-focused multiline TextInput, 4000 char cap
    - Hashtag preview chips that auto-update as you type
    - expo-image-picker + expo-image-manipulator pipeline: resize to
      1080px max-dim, JPEG Q=50 (client-side first-pass compression
      before the mandatory server-side scrub)
    - Live fee estimate + balance guard with a confirmation modal
      ("Опубликовать пост? Цена: 0.00X T · Размер: N KB")
    - Exif: false passed to ImagePicker as an extra privacy layer

  app/(app)/feed/[id].tsx — post detail
    - Full PostCard rendering + detailed info panel (views, likes,
      size, fee, hosting relay, hashtags as tappable chips)
    - Triggers bumpView on mount
    - 410 (on-chain soft-delete) routes back to the feed

  app/(app)/feed/tag/[tag].tsx — hashtag feed

  app/(app)/profile/[address].tsx — rebuilt
    - Twitter-ish profile: avatar, name, address short-form, post count
    - Posts | Инфо tab strip
    - Follow / Unfollow button for non-self profiles (optimistic UI)
    - Edit button on self profile → settings
    - Secondary actions (chat, copy address) when viewing a known contact

Supporting library

  lib/feed.ts — HTTP wrappers + tx builders for every /feed/* endpoint:
    - publishPost (POST /feed/publish, signed)
    - publishAndCommit (publish → on-chain CREATE_POST)
    - fetchPost / fetchStats / bumpView
    - fetchAuthorPosts / fetchTimeline / fetchForYou / fetchTrending /
      fetchHashtag
    - buildCreatePostTx / buildDeletePostTx
    - buildFollowTx / buildUnfollowTx
    - buildLikePostTx / buildUnlikePostTx
    - likePost / unlikePost / followUser / unfollowUser / deletePost
      (high-level helpers that bundle build + submitTx)
    - formatFee, formatRelativeTime, formatCount — Twitter-like display
      helpers

  components/feed/PostCard.tsx — core card component
    - Memoised for performance (N-row re-render on every like elsewhere
      would cost a lot otherwise)
    - Optimistic like toggle with heart-bounce spring animation
    - Hashtag highlighting in body text (tappable → hashtag feed)
    - Long-press context menu (Delete, owner-only)
    - Views / likes / share-link / reply icons in footer row

Navigation cleanup

  - NavBar: removed the SOON pill on the Feed tab (it's shipped now)
  - (app)/_layout: hide NavBar on /compose and /feed/* sub-routes
  - AnimatedSlot: treat /feed/<id>, /feed/tag/<t>, /compose as
    sub-routes so back-swipe-right closes them

Channel removal (client side)

  - lib/types.ts: ContactKind stripped to 'direct' | 'group'; legacy
    'channel' flag removed. `kind` field kept for backward compat with
    existing AsyncStorage records.
  - lib/devSeed.ts: dropped the 5 channel seed contacts.
  - components/ChatTile.tsx: removed channel kindIcon branch.

Dependencies

  - expo-image-manipulator added for client-side image compression.
  - expo-file-system/legacy used for readAsStringAsync (SDK 54 moved
    that API to the legacy sub-path; the new streaming API isn't yet
    stable).

Type check

  - npx tsc --noEmit — clean, 0 errors.

Next (not in this commit)

  - Direct attachment-bytes endpoint on the server so post-detail can
    actually render the image (currently shows placeholder with URL)
  - Cross-relay body fetch via /api/relays + hosting_relay pubkey
  - Mentions (@username) with notifications
  - Full-text search

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

client-app/components/NavBar.tsx

@@ -0,0 +1,150 @@
+/**
+ * NavBar — нижний бар на 5 иконок без подписей.
+ *
+ * Активный таб:
+ *   - иконка заполненная (Ionicons variant без `-outline`)
+ *   - вокруг иконки subtle highlight-блок (чуть светлее bg), радиус 14
+ *   - текст/бейдж остаются как у inactive
+ *
+ * Inactive:
+ *   - outline-иконка, цвет #6b6b6b
+ *   - soon-таб дополнительно dimmed и показывает чип SOON
+ *
+ * Роутинг через expo-router `router.replace` — без стекa, каждый tab это
+ * полная страница без "back" концепции.
+ */
+import React from 'react';
+import { View, Pressable, Text } from 'react-native';
+import { Ionicons } from '@expo/vector-icons';
+import { useRouter, usePathname } from 'expo-router';
+
+type IoniconName = React.ComponentProps<typeof Ionicons>['name'];
+
+interface Item {
+  key: string;
+  href: string;
+  icon: IoniconName;
+  iconActive: IoniconName;
+  badge?: number;
+  soon?: boolean;
+}
+
+export interface NavBarProps {
+  bottomInset?: number;
+  requestCount?: number;
+  notifCount?: number;
+}
+
+export function NavBar({ bottomInset = 0, requestCount = 0, notifCount = 0 }: NavBarProps) {
+  const router = useRouter();
+  const pathname = usePathname();
+
+  const items: Item[] = [
+    { key: 'home',    href: '/(app)/chats',       icon: 'home-outline',         iconActive: 'home',          badge: requestCount },
+    { key: 'add',     href: '/(app)/new-contact', icon: 'search-outline',       iconActive: 'search'                              },
+    { key: 'feed',    href: '/(app)/feed',        icon: 'newspaper-outline',    iconActive: 'newspaper'                           },
+    { key: 'notif',   href: '/(app)/requests',    icon: 'notifications-outline', iconActive: 'notifications', badge: notifCount   },
+    { key: 'wallet',  href: '/(app)/wallet',      icon: 'wallet-outline',       iconActive: 'wallet'                              },
+  ];
+
+  // NavBar active-matching: путь может начинаться с "/chats" ИЛИ с href
+  // напрямую. Вариант `/chats/xyz` тоже считается active для home.
+  const isActive = (href: string) => {
+    // Нормализуем /(app)/chats → /chats
+    const norm = href.replace(/^\/\(app\)/, '');
+    return pathname === norm || pathname.startsWith(norm + '/');
+  };
+
+  return (
+    <View
+      style={{
+        flexDirection: 'row',
+        alignItems: 'center',
+        justifyContent: 'space-around',
+        backgroundColor: '#000000',
+        borderTopWidth: 1,
+        borderTopColor: '#0f0f0f',
+        paddingTop: 8,
+        paddingBottom: Math.max(bottomInset, 8),
+      }}
+    >
+      {items.map((it) => {
+        const active = isActive(it.href);
+        return (
+          <Pressable
+            key={it.key}
+            onPress={() => {
+              if (it.soon) return;
+              router.replace(it.href as never);
+            }}
+            hitSlop={6}
+            style={({ pressed }) => ({
+              flex: 1,
+              alignItems: 'center',
+              justifyContent: 'center',
+              paddingVertical: 4,
+              opacity: pressed ? 0.65 : 1,
+            })}
+          >
+            <View
+              style={{
+                // highlight-блок вокруг active-иконки
+                width: 52,
+                height: 36,
+                borderRadius: 14,
+                alignItems: 'center',
+                justifyContent: 'center',
+                position: 'relative',
+              }}
+            >
+              <Ionicons
+                name={active ? it.iconActive : it.icon}
+                size={26}
+                color={active ? '#ffffff' : it.soon ? '#3a3a3a' : '#6b6b6b'}
+              />
+              {it.badge && it.badge > 0 ? (
+                <View
+                  style={{
+                    position: 'absolute',
+                    top: 2,
+                    right: 8,
+                    minWidth: 16,
+                    height: 16,
+                    paddingHorizontal: 4,
+                    borderRadius: 8,
+                    backgroundColor: '#1d9bf0',
+                    alignItems: 'center',
+                    justifyContent: 'center',
+                    borderWidth: 1.5,
+                    borderColor: '#000',
+                  }}
+                >
+                  <Text style={{ color: '#fff', fontSize: 9, fontWeight: '700' }}>
+                    {it.badge > 99 ? '99+' : it.badge}
+                  </Text>
+                </View>
+              ) : null}
+              {it.soon && (
+                <View
+                  style={{
+                    position: 'absolute',
+                    top: -2,
+                    right: 2,
+                    paddingHorizontal: 4,
+                    paddingVertical: 1,
+                    borderRadius: 4,
+                    backgroundColor: '#1a1a1a',
+                  }}
+                >
+                  <Text style={{ color: '#8b8b8b', fontSize: 7, fontWeight: '700', letterSpacing: 0.3 }}>
+                    SOON
+                  </Text>
+                </View>
+              )}
+            </View>
+          </Pressable>
+        );
+      })}
+    </View>
+  );
+}