refactor: split domain-tools.spec.ts into per-domain test files

Separate schedule, secret, and human-input tests into individual files
for better organization and discoverability.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>
Signed-off-by: betterclever <paliwal.pranjal83@gmail.com>

Author: betterclever