stop baking _SOLSTONE_JOURNAL_OVERRIDE into generated service files
sol service install unconditionally set the journal override to the
resolved path, which caused path mismatches when the project journal/
is a symlink — the supervisor and its child processes would see different
path strings for the same directory, breaking singleton lock detection
and allowing duplicate supervisor instances.
The override is only needed for dev/test sandboxes. The default
project-root resolution works correctly for production service files.
Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>