⚡ Bolt: Optimize Chat UI rendering in Ink

[the-abra]

💡 What:

• Wrapped the ChatMessage component in React.memo() to prevent unnecessary re-renders when props haven't changed.
• Used useMemo for the expensive marked.parse markdown parsing in ChatMessage based on the message content identity.
• Used useMemo in App.tsx for creating the staticItems array to prevent mapping over the entire history array on every single chunk stream.

🎯 Why:
During streaming (when streamingText updates frequently), the UI forces re-renders. Previously, this caused the history.map to run on every chunk, and could potentially cause ChatMessage to re-parse markdown heavily. React and Ink need optimizations for continuous updates like streaming.

📊 Impact:
Reduces CPU spike and unnecessary component re-evaluations during text streaming by caching parsed markdown and preventing O(N) array mapping on every token chunk. Overall smoother terminal UI experience.

🔬 Measurement:
To verify, initiate a long conversation with streaming enabled and observe reduced CPU usage and no jitter in the terminal output. Code tests (pnpm test) pass properly to ensure no functionality is broken.

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PR created automatically by Jules for task 4183969796264143660 started by @the-abra

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