POST /backpacks/read, a thin forward like /kits/uses: the body is stamped
`backpacks.read` whatever it names, so the route can only ever read. Nothing is
kept here. The bigger backpack an event lends is a permission in an ordinary
perm.sync (D337) and needs nothing new. Still protocol 14 (D332); one test.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01E14m6SuuY6i1vASFeGDBeY