fix(chat): make search bar clickable (was overlayed by message list) (#492)

* fix(chat): make search bar clickable by giving ChatMessageList a vertical layout

The search bar (AnimatedVisibility) and the message LazyColumn were
emitted as siblings with no container. The call site is a Box, which
overlays children — so the LazyColumn rendered on top of the search bar,
intercepting every pointer event. The bar stayed visible but was dead
(nothing inside clickable: input, nav arrows, close).

Wrap ChatMessageList's children in a Column so the bar occupies real
layout space above the list; the LazyColumn now takes weight(1f) and
scrolls independently. Fixes #490.

* refactor(chat): simplify search-list LazyColumn modifier

Use fillMaxWidth().weight(1f) instead of fillMaxSize().weight(1f) inside
the new Column — weight already claims the remaining vertical space, so
fillMaxSize was redundant/contradictory (Sourcery review nit).

Note: the Sourcery 'use LocalHermesStatusColors' suggestion on the search
bar Surface is a false positive — that rule covers SEMANTIC status colors
(success/warning/error/info) only. surfaceContainerLow/outline are neutral
Material surface chrome, not status colors; LocalHermesStatusColors does
not even expose them. The corresponding status dot correctly uses StatusRed.

app/src/main/java/com/m57/hermescontrol/ui/chat/ChatScreen.kt

@@ -1402,6 +1402,11 @@ private fun ChatMessageList(
     onLastAnimatedMessageIdChange: (String?) -> Unit,
     viewModel: ChatViewModel,
 ) {
+    // Lay children out vertically so the search bar occupies real layout space
+    // ABOVE the message list. Without this container the call site is a Box,
+    // which overlays the LazyColumn on top of the search AnimatedVisibility and
+    // swallows every tap on the bar (bar visible but not clickable).
+    Column(modifier = Modifier.fillMaxSize()) {
         // Search bar
         androidx.compose.animation.AnimatedVisibility(
             visible = isSearchActive,
@@ -1441,7 +1446,7 @@ private fun ChatMessageList(
 
         LazyColumn(
             state = listState,
-        modifier = Modifier.fillMaxSize(),
+            modifier = Modifier.fillMaxWidth().weight(1f),
             contentPadding = PaddingValues(vertical = 8.dp),
         ) {
             itemsIndexed(
@@ -1506,6 +1511,7 @@ private fun ChatMessageList(
                 }
             }
         }
+    }
 }
 
 @Composable