fix: ChatBubble crash and DeepSeek API compatibility

- Fix ChatBubble to handle non-string content with String() wrapper
- Fix API route to use generateText for non-streaming requests
- Add @ai-sdk/openai-compatible for non-OpenAI providers (DeepSeek, etc.)
- Use Chat Completions API instead of Responses API for compatible providers
- Update ChatBubble tests and fix component exports to kebab-case
- Remove stale PascalCase ChatBubble.tsx file

src/components/features/draft/DraftViewSheet.tsx

@@ -1,6 +1,6 @@
 'use client';
 
-import { useState } from 'react';
+import { useState, useEffect } from 'react';
 import { Trash2 } from 'lucide-react';
 import { useChatStore } from '@/lib/store/chat-store';
 import { Sheet } from './Sheet';
@@ -40,6 +40,11 @@ export function DraftViewSheet() {
   const [toastShow, setToastShow] = useState(false);
   const [toastMessage, setToastMessage] = useState('');
 
+  // Fix: Reset toast when opening a new draft
+  useEffect(() => {
+    setToastShow(false);
+  }, [currentDraft, showDraftView]);
+
   const showCopyToast = (message: string = 'Copied to clipboard!') => {
     setToastMessage(message);
     setToastShow(true);