Drop the every-launch (re)registration thread. File association is now set up
once via the first-launch prompt (Yes → register + set default; No → decline,
persisted as file_assoc_enabled) and managed afterwards by the FILEASSOC
command. set_default_app now registers the handler entries (.desktop / mime /
ProgIDs) itself before asking the OS to default to us, since boot no longer
does — so the default never points at a missing handler.
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>