presenceUser()/userSlug() now resolve the authenticated user: a plain
/api/me fetch (GPL no-link rule — no closed contract import) races the WASM
boot and is awaited before presence/comments bind. `?user=`/`?libowner=`
overrides are gated behind VITE_ALLOW_USER_OVERRIDE=1 (dev script + e2e
harnesses set it; prod builds never do). Anonymous/example-backend sessions
keep the pre-auth slug fallback. Fixes prod's empty presence (everyone was
"local-user", deduped as own tabs) and comment authorship in one move.
Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01A42xfPFNdfsUt9eowkC9eM
6675c1f0fc