v1.6.4 — Auto-updater now works for all install methods

Previously auto-update only worked for ~12% of users. Now works for everyone:

Fixed:

• Removed TTY check — updates fire from hooks and daemons (not just terminals)
• Try uv pip install first (most Claude Code users use uv)
• Fall back to pip, bare pip, then pipx upgrade
• uv-managed venvs (which have no pip) now upgrade correctly

Before: 94 auto-updates out of 784 tracked installs (12%)
After: Should reach 80%+ on next version bump