fix: handle stdin error in ponytail-mode-tracker to avoid uncaught crash (#147)

[Lakshya77089]

Summary

Fixes #147. hooks/ponytail-mode-tracker.js registered stdin.on('data') and stdin.on('end') but no stdin.on('error') handler. When stdin closes abnormally (broken pipe, parent crash), Node emits an error event on the stream; with no listener this surfaces as an uncaught exception, crashing the hook with a non-zero exit code.

Fix

Register an error handler that calls process.exit(0) before the data/end listeners. This preserves the hook contract — always exit 0, never block session start.

let input = '';
// Exit cleanly if stdin errors (broken pipe, parent crash) — never block session start
process.stdin.on('error', () => { process.exit(0); });
process.stdin.on('data', chunk => { input += chunk; });

Notes

• This is the only stdin-reading hook in hooks/, so no other files need the same change.
• Severity per the issue: HIGH — unhandled stream error → uncaught exception → hook crashes non-zero.