feat(launcher): migrate to launch-scaffolder (server-url, port 8000)

Adds panll.launcher.a2ml at the repo root and the scaffolder-generated
panll-launcher.sh next to it. Replaces the hand-written launcher from
~/.desktop-tools/. Desktop shortcut repointed.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

Author: hyperpolymath