Document the multi-remote release, publish matching store metadata,
and advance the version once from the released 0.1.3 base.

Support Alpine/musl and Debian/glibc hosts, lock downloaded and
Gradle artifacts, and verify native and APK security properties.

Validate persisted state and destination boundaries, make interruption
and mirror deletion explicit, and keep scheduled work singular.

Let each folder select a named SSH endpoint and migrate the published
0.1.x configuration without discarding its folders or host pin.

versionCode 4. Bound the SSH handshake so a stalled server cannot hang
a sync. Persist config, key, and host pin atomically so an interrupted
write cannot corrupt state. Replace the chained one-time jobs with
periodic work that survives reboots; the schedule floor is now
WorkManager's 15-minute minimum.

Checksum-pin every downloaded toolchain archive. Before publishing,
verify the APK was built from HEAD, the tag matches versionName,
apksigner passes, and the tree is clean; publish a sha256 sidecar
and treat published assets as immutable. Compare full unsigned APKs
in verify-repro and run the Android unit tests in CI.

Persist config, key blob, and host pin via AtomicFile so an
interrupted write cannot corrupt state. Validate the port, clear the
host pin when the remote changes, cap imported key size, time out
native helpers, and escalate rsync termination to destroyForcibly.
Serialize manual and scheduled syncs behind a mutex.

Replace the chained one-time jobs with plain periodic work: it
survives reboots without a boot receiver and cannot silently die
like a broken chain. Costs the sub-15-minute interval, which photo
backup does not need. Document the floor and that syncs run on any
unmetered network, not only WiFi.

versionCode 3. Drop --mkpath so remotes with an rsync older than 3.2.3
(stock macOS included) can receive syncs; rsync still creates the final
remote path component on its own. NDK host toolchain detection so the
native build also runs on macOS hosts.

rsync forwards --mkpath to the remote side when sending, so a remote
rsync older than 3.2.3 (notably stock macOS, whose openrsync is
"rsync 2.6.9 compatible") rejects every sync with "unrecognized
option '--mkpath'".

rsync creates the final component of the destination path on its own,
so flat remote paths keep working everywhere, including the documented
rrsync setup whose root is pre-created. Only a nested remote path with
missing parents now needs a one-time mkdir -p on the server; the log
shows rsync's error when it is missing.

Reported-by: jsvk
Link: https://codeberg.org/0xlena/rsend/pulls/1

versionCode 2. Empty-path and config-corruption fixes, rsync process
cleanup on stopped syncs, keygen error reporting, and the store icon.