The engine now executes only inside the app (libsql): subminer sync
rebuilds the equivalent --sync-cli argv and spawns the discovered app
binary with the terminal attached (stdin for ssh prompts, raw NDJSON
stdout, exit-code passthrough). The bun:sqlite driver binding and the
launcher-side engine shims are gone; flow tests moved to
src/core/services/stats-sync/sync-flow.test.ts, ssh tests to src, and
the merge suite now runs through the libsql driver the app ships.
Remote temp dirs are now created and removed by the remote SubMiner
itself (sync --make-temp / --remove-temp, validated against its own
tmpdir) instead of mktemp/rm, and the flow detects the remote shell
(POSIX, cmd, PowerShell) to pick quoting and SubMiner install-location
candidates - %LOCALAPPDATA% app install, launcher shim, or PATH - with
no POSIX PATH prefix on Windows. Remote temp paths are normalized to
forward slashes for scp and the CLI. Verified end-to-end against a
throwaway sshd with the app binary as the resolved remote command.
Move snapshot/merge/quiescence engine and ssh helpers from launcher/sync
into src/core/services/stats-sync, parameterized on a minimal SyncDb
driver. The launcher binds it to bun:sqlite via launcher/sync/bun-driver;
the sync command becomes a thin adapter over the shared sync flow.