v0.5.3 — Windows without Git Bash

• Windows: briefing runs without Git Bash. Each hook script has a small
  <name>.exe next to it, which Claude Code starts on Windows and which runs
  the script with the first working Python (python3, python, py -3;
  the Microsoft Store stub is skipped), in UTF-8 mode. Linux and macOS start
  the scripts as before.
• Windows: skills from plugins resolve. The check that a skill lies inside its
  plugin compared paths with / and never matched there.
• briefing-doctor is a small script instead of a symlink, so it exists in a
  Windows checkout and runs from PowerShell and cmd too.
• With HOME unset, briefing uses the platform's home directory instead of
  none.
• hooks.json gained "args": [] on every entry, so Codex asks to trust the
  hooks once more.