Content multica creates in inbox/ is owned multica:multica, so obsync fell
into "other" (---) and Sync could neither read nor upload Wong's
submissions. Found after the real Sync sign-in on spaceship-earth; the
earlier verify only tested the obsync -> multica direction.
Shared folders now carry user:obsync:rwx as an access and a default entry
alongside the shared user's, and verify tests the multica -> obsync
direction (read + rewrite, as merge needs). Second run changed=0.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
