feat: allow model switching mid convo

src/routes/(app)/+page.svelte

@@ -832,10 +832,7 @@
 					? 'max-w-full'
 					: 'max-w-2xl md:px-0'} mx-auto w-full px-4"
 			>
-				<ModelSelector
-					bind:selectedModels
-					disabled={messages.length > 0 && !selectedModels.includes('')}
-				/>
+				<ModelSelector bind:selectedModels />
 			</div>
 
 			<div class=" h-full w-full flex flex-col py-8">

src/routes/(app)/c/[id]/+page.svelte

@@ -863,10 +863,7 @@
 						? 'max-w-full'
 						: 'max-w-2xl md:px-0'} mx-auto w-full px-4"
 				>
-					<ModelSelector
-						bind:selectedModels
-						disabled={messages.length > 0 && !selectedModels.includes('')}
-					/>
+					<ModelSelector bind:selectedModels />
 				</div>
 
 				<div class=" h-full w-full flex flex-col py-8">