feat: add DeepSeek extreme reasoning tier

docker/web/ModelSelector.svelte

@@ -10,16 +10,19 @@
 	const strengths = [
 		{ key: 'light', label: '轻度' },
 		{ key: 'medium', label: '中' },
-		{ key: 'high', label: '高' }
+		{ key: 'high', label: '高' },
+		{ key: 'extreme', label: '极高' }
 	];
 
 	const allowed = new Set([
 		'chat-light',
 		'chat-medium',
 		'chat-high',
+		'chat-extreme',
 		'work-light',
 		'work-medium',
-		'work-high'
+		'work-high',
+		'work-extreme'
 	]);
 
 	$: selected = allowed.has(selectedModels?.[0]) ? selectedModels[0] : 'chat-medium';