fix(feed): card spacing, action-row distribution, tab strip, detail inset

- PostCard rows got cramped paddings and a near-invisible divider.
  Increased paddingTop 12→16, paddingBottom 12→18, paddingHorizontal
  14→16; divider colour #141414→#222222 so the seam between posts is
  legible on OLED blacks.
- Action row (chat / ❤ / view / share) used a fixed gap:32 + spacer.
  Reworked to four flex:1 cells with justifyContent: space-between,
  so the first three icons distribute evenly across the row and share
  pins to the right edge. Matches Twitter's layout where each action
  occupies a quarter of the row regardless of label width.
- Feed tab strip (Подписки / Для вас / В тренде) used flex:1 +
  gap:10 which bunched the three labels together visually. Switched
  to justifyContent: space-between + paddingHorizontal:20 so each
  tab hugs its label and the three labels spread to the edges with
  full horizontal breathing room.
- Post detail screen (/feed/[id]) and hashtag feed (/feed/tag/[tag])
  were missing the safe-area top inset — their headers butted right
  against the status bar / notch. Added useSafeAreaInsets().top as
  paddingTop on the outer View, matching the rest of the app.

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

client-app/app/(app)/feed/index.tsx

@@ -158,17 +158,18 @@ export default function FeedScreen() {
     <View style={{ flex: 1, backgroundColor: '#000000', paddingTop: insets.top }}>
       <TabHeader title="Лента" />
 
-      {/* Tab strip — больше воздуха между табами. Горизонтальный padding
-          на контейнере + gap между Pressable'ами делает табы "breathable",
-          индикатор активной вкладки — тонкая полоска только под текстом,
-          шириной примерно с лейбл. */}
+      {/* Tab strip — три таба, равномерно распределены по ширине
+          (justifyContent: space-between). Каждый Pressable hug'ает
+          свой контент — табы НЕ тянутся на 1/3 ширины, а жмутся к
+          своему лейблу, что даёт воздух между ними. Индикатор активной
+          вкладки — тонкая полоска под лейблом. */}
       <View
         style={{
           flexDirection: 'row',
-          paddingHorizontal: 12,
-          gap: 10,
+          justifyContent: 'space-between',
+          paddingHorizontal: 20,
           borderBottomWidth: 1,
-          borderBottomColor: '#141414',
+          borderBottomColor: '#1f1f1f',
         }}
       >
         {(Object.keys(TAB_LABELS) as TabKey[]).map(key => (
@@ -176,33 +177,31 @@ export default function FeedScreen() {
             key={key}
             onPress={() => setTab(key)}
             style={({ pressed }) => ({
-              flex: 1,
               alignItems: 'center',
               paddingVertical: 16,
-              backgroundColor: pressed ? '#0a0a0a' : 'transparent',
+              paddingHorizontal: 6,
+              opacity: pressed ? 0.6 : 1,
             })}
           >
             <Text
               style={{
                 color: tab === key ? '#ffffff' : '#6a6a6a',
                 fontWeight: tab === key ? '700' : '500',
-                fontSize: 14,
+                fontSize: 15,
                 letterSpacing: -0.1,
               }}
             >
               {TAB_LABELS[key]}
             </Text>
-            {tab === key && (
-              <View
-                style={{
-                  marginTop: 10,
-                  width: 32,
-                  height: 3,
-                  borderRadius: 1.5,
-                  backgroundColor: '#1d9bf0',
-                }}
-              />
-            )}
+            <View
+              style={{
+                marginTop: 10,
+                width: tab === key ? 28 : 0,
+                height: 3,
+                borderRadius: 1.5,
+                backgroundColor: '#1d9bf0',
+              }}
+            />
           </Pressable>
         ))}
       </View>