fix: guard final writeHookOutput against stdout EPIPE in ponytail-activate (#149)

[Lakshya77089]

Summary

Fixes #149. The final writeHookOutput('SessionStart', mode, output) call at ponytail-activate.js:72 was the only operation in the file left outside a try/catch — setMode and the statusline detection are both guarded.

writeHookOutput ends in a bare process.stdout.write(...) (ponytail-runtime.js:42) with no internal guard, so if stdout is closed or the pipe to the host breaks at hook exit, process.stdout.write throws EPIPE, which becomes an uncaught exception and crashes the hook with a non-zero exit code.

Fix

Wrap the final write in try/catch, matching the never-block-session-start posture used everywhere else in the file:

try {
  writeHookOutput('SessionStart', mode, output);
} catch (e) {
  // Silent fail — stdout closed/EPIPE at hook exit must not surface as a hook failure
}

node --check passes.

Credit

Thanks to @Indrajeet-Badhel for triaging this issue and confirming the approach — this PR implements the same guard discussed there.