#10 fix(cli): use subprocess IPC for non-blocking native calls

Summary

Fixes the TUI loader freezing during data loading by running heavy native Rust functions in a subprocess.

Problem

The CLI TUI loader/spinner would freeze for 100-500ms while native Rust functions executed, blocking the Node.js event loop.

Solution

• Add native-runner.ts: subprocess that reads method/args from stdin, executes native function, writes result to stdout
• Add *NativeAsync() wrappers that spawn subprocess and communicate via stdin/stdout pipes
• Update useData.ts to use async subprocess versions

Benefits over temp file approach

Aspect	Temp Files	stdin/stdout
File I/O	2 writes + 2 reads	None
Cleanup	Manual unlinkSync	Automatic
Crash safety	Leftover files	Clean
Security	Data on disk	In memory

Testing

The spinner now animates smoothly throughout the entire data loading process.