Implement batch/parallel file processing for performance optimization #4712
Description
What would you like to be added?
Parallel processing capability in read-many-files.ts to handle multiple files concurrently instead of sequential processing, using Promise.allSettled() or similar patterns.
Why is this needed?
Current sequential file processing blocks the event loop and creates poor UX for large projects. Based on Han5991's recent async file detection improvements (#3286), we can now safely implement parallel processing for 20-80% performance gains.
Additional context
- Building on the async foundation from commit 45b7649
- Affects core file operations used throughout the CLI
- Maintains error handling while improving throughput