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/components/feed/PostCard.tsx

@@ -173,11 +173,12 @@ function PostCardInner({ post, likedByMe, onStatsChanged, onDeleted, compact }:
       onLongPress={onLongPress}
       style={({ pressed }) => ({
         flexDirection: 'row',
-        paddingHorizontal: 14,
-        paddingVertical: compact ? 10 : 12,
+        paddingHorizontal: 16,
+        paddingTop: compact ? 12 : 16,
+        paddingBottom: compact ? 14 : 18,
         backgroundColor: pressed ? '#080808' : 'transparent',
         borderBottomWidth: 1,
-        borderBottomColor: '#141414',
+        borderBottomColor: '#222222',
       })}
     >
       {/* Avatar column */}
@@ -246,58 +247,69 @@ function PostCardInner({ post, likedByMe, onStatsChanged, onDeleted, compact }:
           </View>
         )}
 
-        {/* Action row */}
+        {/* Action row — 4 evenly-spaced buttons (Twitter-style). Each is
+            wrapped in a flex: 1 container so even if one label is
+            wider than another, visual spacing between centres stays
+            balanced. */}
         <View
           style={{
             flexDirection: 'row',
             alignItems: 'center',
-            marginTop: 8,
-            gap: 32,
+            justifyContent: 'space-between',
+            marginTop: 12,
+            paddingRight: 4,
           }}
         >
-          <ActionButton
-            icon="chatbubble-outline"
-            label={formatCount(0) /* replies count — not implemented yet */}
-            onPress={onOpenDetail}
-          />
-          <Pressable
-            onPress={onToggleLike}
-            disabled={busy}
-            hitSlop={8}
-            style={({ pressed }) => ({
-              flexDirection: 'row', alignItems: 'center', gap: 6,
-              opacity: pressed ? 0.5 : 1,
-            })}
-          >
-            <Animated.View style={{ transform: [{ scale: heartScale }] }}>
-              <Ionicons
-                name={localLiked ? 'heart' : 'heart-outline'}
-                size={16}
-                color={localLiked ? '#e0245e' : '#6a6a6a'}
-              />
-            </Animated.View>
-            <Text
-              style={{
-                color: localLiked ? '#e0245e' : '#6a6a6a',
-                fontSize: 12,
-                fontWeight: localLiked ? '600' : '400',
-              }}
+          <View style={{ flex: 1, alignItems: 'flex-start' }}>
+            <ActionButton
+              icon="chatbubble-outline"
+              label={formatCount(0) /* replies count — not implemented yet */}
+              onPress={onOpenDetail}
+            />
+          </View>
+          <View style={{ flex: 1, alignItems: 'flex-start' }}>
+            <Pressable
+              onPress={onToggleLike}
+              disabled={busy}
+              hitSlop={8}
+              style={({ pressed }) => ({
+                flexDirection: 'row', alignItems: 'center', gap: 6,
+                opacity: pressed ? 0.5 : 1,
+              })}
             >
-              {formatCount(localLikeCount)}
-            </Text>
-          </Pressable>
-          <ActionButton
-            icon="eye-outline"
-            label={formatCount(post.views)}
-          />
-          <View style={{ flex: 1 }} />
-          <ActionButton
-            icon="share-outline"
-            onPress={() => {
-              // Placeholder — copy postID to clipboard in a future PR.
-              Alert.alert('Ссылка', `dchain://post/${post.post_id}`);
-            }}
-          />
+              <Animated.View style={{ transform: [{ scale: heartScale }] }}>
+                <Ionicons
+                  name={localLiked ? 'heart' : 'heart-outline'}
+                  size={16}
+                  color={localLiked ? '#e0245e' : '#6a6a6a'}
+                />
+              </Animated.View>
+              <Text
+                style={{
+                  color: localLiked ? '#e0245e' : '#6a6a6a',
+                  fontSize: 12,
+                  fontWeight: localLiked ? '600' : '400',
+                }}
+              >
+                {formatCount(localLikeCount)}
+              </Text>
+            </Pressable>
+          </View>
+          <View style={{ flex: 1, alignItems: 'flex-start' }}>
+            <ActionButton
+              icon="eye-outline"
+              label={formatCount(post.views)}
+            />
+          </View>
+          <View style={{ alignItems: 'flex-end' }}>
+            <ActionButton
+              icon="share-outline"
+              onPress={() => {
+                // Placeholder — copy postID to clipboard in a future PR.
+                Alert.alert('Ссылка', `dchain://post/${post.post_id}`);
+              }}
+            />
+          </View>
         </View>
       </View>
     </Pressable>