fix: let the composer's model selector shrink so narrow containers keep every control visible (#28912)

src/lib/components/chat/MessageInput.svelte

@@ -2141,7 +2141,7 @@
 							</div>
 
 							<div class=" flex justify-between mt-0.5 mb-2 mx-0.5 max-w-full" dir="ltr">
-								<div class="ml-1 self-end flex items-center flex-1 min-w-0">
+								<div class="ml-1 self-end flex items-center shrink-0">
 									<InputMenu
 										bind:files
 										selectedModels={selectedModelIds}
@@ -2476,7 +2476,7 @@
 									</div>
 								</div>
 
-								<div class="self-end flex space-x-1 mr-1 shrink-0 gap-[0.03125rem]">
+								<div class="self-end flex space-x-1 mr-1 min-w-0 gap-[0.03125rem]">
 									<div class="flex min-w-0 max-w-[10rem] items-center sm:max-w-[13rem]">
 										<ModelSelector
 											bind:this={modelSelector}