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.
Sync window drops the launcher-missing warning (self-spawn always works),
the setup checklist explains automatic remote discovery (SubMiner on
PATH, macOS /Applications, or the optional launcher), and the remote
resolver gains tests for app-binary fallback and --remote-cmd probing.