MIDI clock sync + note output over USB/BLE (v0.18.0)

Add a MIDI Sync settings card (before the binding cards) with Send and Receive
MIDI clock toggles, both off by default and persisted.

Send: a dedicated thread emits clock (0xF8) at 24 PPQN plus Start/Stop on the
transport edges to every attached MIDI device (USB + Bluetooth), and — because a
sequencer should drive gear, not just its tempo — also forwards the tracks'
note-on/off on each cell's MIDI channel. Notes are queued from the audio thread
through a lock-free ring and drained by the send thread, mirroring the mono-per-
track cell lifecycle; stop/pause/panic release everything so external notes never
hang. (Per-channel Arpeggiator/Transposer are internal FX and aren't reflected.)

Receive: MidiInput now forwards real-time bytes to the clock module, which follows
an external clock — Start/Continue starts the transport, Stop pauses it, and the
pulse rate drives the tempo (a tempo + transport follow, not a sample-locked slave).

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

app/build.gradle.kts

@@ -22,8 +22,8 @@ android {
         // (android.media.midi) and AAudio low-latency audio we rely on.
         minSdk = 26
         targetSdk = 34
-        versionCode = 42
-        versionName = "0.16.1"
+        versionCode = 44
+        versionName = "0.18.0"
 
         // We provide our own instrumentation runner if/when tests are added.
         testInstrumentationRunner = "androidx.test.runner.AndroidJUnitRunner"