refactor: use Nuxt 4 directory structure

app/composables/useAiProvider.ts

@@ -0,0 +1,46 @@
+import { createDeepSeek } from '@ai-sdk/deepseek'
+import { createOpenRouter } from '@openrouter/ai-sdk-provider'
+import { createOpenAI } from '@ai-sdk/openai'
+import {
+  extractReasoningMiddleware,
+  wrapLanguageModel,
+  type LanguageModelV1,
+} from 'ai'
+
+export const useAiModel = () => {
+  const { config, aiApiBase } = useConfigStore()
+  let model: LanguageModelV1
+
+  if (config.ai.provider === 'openrouter') {
+    const openRouter = createOpenRouter({
+      apiKey: config.ai.apiKey,
+      baseURL: aiApiBase,
+    })
+    model = openRouter(config.ai.model, {
+      includeReasoning: true,
+    })
+  } else if (
+    config.ai.provider === 'deepseek' ||
+    config.ai.provider === 'siliconflow' ||
+    // Special case if model name includes 'deepseek'
+    // This ensures compatibilty with providers like Siliconflow
+    config.ai.model?.toLowerCase().includes('deepseek')
+  ) {
+    const deepSeek = createDeepSeek({
+      apiKey: config.ai.apiKey,
+      baseURL: aiApiBase,
+    })
+    model = deepSeek(config.ai.model)
+  } else {
+    const openai = createOpenAI({
+      apiKey: config.ai.apiKey,
+      baseURL: aiApiBase,
+    })
+    model = openai(config.ai.model)
+  }
+
+  return wrapLanguageModel({
+    model,
+    middleware: extractReasoningMiddleware({ tagName: 'think' }),
+  })
+}