Merge pull request #2673 from vitorpamplona/claude/fix-chatroom-list-reuse-Wkz10

Fix double padding in two-pane chat layout

amethyst/src/main/java/com/vitorpamplona/amethyst/ui/screen/loggedIn/chats/rooms/twopane/MessagesTwoPane.kt

@@ -21,16 +21,19 @@
 package com.vitorpamplona.amethyst.ui.screen.loggedIn.chats.rooms.twopane
 
 import androidx.compose.foundation.layout.Box
+import androidx.compose.foundation.layout.PaddingValues
 import androidx.compose.foundation.layout.fillMaxSize
 import androidx.compose.foundation.layout.padding
 import androidx.compose.foundation.layout.systemBarsPadding
 import androidx.compose.material3.windowsizeclass.WindowWidthSizeClass
 import androidx.compose.runtime.Composable
+import androidx.compose.runtime.CompositionLocalProvider
 import androidx.compose.runtime.remember
 import androidx.compose.runtime.rememberCoroutineScope
 import androidx.compose.ui.Alignment
 import androidx.compose.ui.Modifier
 import androidx.compose.ui.platform.LocalContext
+import androidx.compose.ui.unit.dp
 import com.google.accompanist.adaptive.FoldAwareConfiguration
 import com.google.accompanist.adaptive.HorizontalTwoPaneStrategy
 import com.google.accompanist.adaptive.TwoPane
@@ -38,6 +41,7 @@ import com.google.accompanist.adaptive.calculateDisplayFeatures
 import com.vitorpamplona.amethyst.commons.ui.feeds.FeedContentState
 import com.vitorpamplona.amethyst.ui.components.getActivity
 import com.vitorpamplona.amethyst.ui.layouts.DisappearingScaffold
+import com.vitorpamplona.amethyst.ui.layouts.LocalDisappearingScaffoldPadding
 import com.vitorpamplona.amethyst.ui.navigation.bottombars.AppBottomBar
 import com.vitorpamplona.amethyst.ui.navigation.navs.INav
 import com.vitorpamplona.amethyst.ui.navigation.routes.Route
@@ -92,7 +96,16 @@ fun MessagesTwoPane(
     ) { padding ->
         TwoPane(
             first = {
-                Box(Modifier.fillMaxSize().systemBarsPadding(), contentAlignment = Alignment.BottomEnd) {
+                // The chatroom-list pane owns its own TabRow, so it doesn't
+                // need the outer scaffold's top bar to layer over it. Apply
+                // the scaffold padding directly and reset
+                // LocalDisappearingScaffoldPadding to zero so descendants
+                // (e.g. the LazyColumn inside ChatroomListFeedView via
+                // rememberFeedContentPadding) don't add the bar inset a
+                // second time, which would otherwise show up as a gap
+                // between the TabRow and the first list item.
+                CompositionLocalProvider(LocalDisappearingScaffoldPadding provides PaddingValues(0.dp)) {
+                    Box(Modifier.fillMaxSize().padding(padding), contentAlignment = Alignment.BottomEnd) {
                         ChatroomList(
                             knownFeedContentState,
                             newFeedContentState,
@@ -104,8 +117,13 @@ fun MessagesTwoPane(
                             ChannelFabColumn(nav)
                         }
                     }
+                }
             },
             second = {
+                // The chat-view pane brings its own DisappearingScaffold
+                // (with its own chat header), so it stays edge-to-edge under
+                // the outer search bar via systemBarsPadding instead of the
+                // scaffold padding.
                 Box(Modifier.fillMaxSize().systemBarsPadding()) {
                     twoPaneNav.innerNav.value?.let {
                         if (it is Route.Room) {