The initial import was latency-bound: the push loop uploaded blobs strictly
serially, doing an Exists round-trip then a Put per blob (~2-3N sequential
round-trips against the hub).
- Upload unique blobs in parallel (errgroup, 16 in flight) — the main win.
- Drop the separate Exists round-trip: the backend's Put is idempotent and
the hub already skips content it has (reported during signing), so the
check was redundant.
- Session.OnProgress emits upload progress (done/total files + bytes) from
the push phase; the CLI renders an in-place bar on a TTY and periodic
percentage lines otherwise, wired into `bdrive init`'s initial cycle and
`bdrive sync`. The daemon stays silent.
Multi-device convergence tests pass with -race; new TestPushProgress covers
the progress emission.
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01R7Q9ZKSZRTdvrSJkYLUmYs
