fix: Improve thinking tag removal with more aggressive cleaning

- Add multiple regex passes to handle various think tag scenarios
- Remove standalone <think> and </think> tags that might remain
- Clean leading whitespace after tag removal
- Add debug logging to track text cleaning process
- Handle streaming cases where tags appear before closing tags arrive

This provides more robust cleaning to ensure no think tags appear
in the final message content during streaming scenarios.

examples/chat-ui/src/components/ChatMessage.tsx

@@ -34,7 +34,7 @@ const ChatMessage: React.FC<ChatMessageProps> = ({
         className={` 
         ${
           message.role === "user"
-            ? "max-w-[80%] rounded-2xl px-3 py-2 border border-zinc-200/10 bg-zinc-100 text-black"
+            ? "max-w-[80%] rounded-2xl px-3 py-2 border border-zinc-200/10 bg-white text-black"
             : " text-zinc-900 w-full"
         }`}
       >

examples/chat-ui/src/hooks/useStreamResponse.ts

@@ -271,9 +271,18 @@ export const useStreamResponse = ({
                         // Remove thinking tags from the display text (they should be extracted by middleware)
                         let cleanedResponse = aiResponse
                         if (supportsReasoning(selectedModel)) {
+                            debugLog(`[useStreamResponse] Original response:`, aiResponse.substring(0, 100))
+                            // Remove complete thinking blocks
                             cleanedResponse = aiResponse.replace(/<think>[\s\S]*?<\/think>/g, '').trim()
-                            // Also handle unclosed think tags
+                            // Remove unclosed think tags (everything from <think> to end)
                             cleanedResponse = cleanedResponse.replace(/<think>[\s\S]*$/g, '').trim()
+                            // Remove any remaining opening think tags
+                            cleanedResponse = cleanedResponse.replace(/<think>/g, '').trim()
+                            // Remove any remaining closing think tags
+                            cleanedResponse = cleanedResponse.replace(/<\/think>/g, '').trim()
+                            // Clean up any remaining whitespace or newlines at the start
+                            cleanedResponse = cleanedResponse.replace(/^\s+/, '')
+                            debugLog(`[useStreamResponse] Cleaned response:`, cleanedResponse.substring(0, 100))
                         }
 
                         setConversations((prev) => {