fix(radio): undo the playback the vendor's tune starts on its own

1.1.0 dropped the srcPlayRadio call after tuning and assumed that was
enough to change station in silence. It is not. RadioService's own tune
calls AudioController.requestMuted(false), which requests the audio focus
and unmutes the tuner, so the radio starts playing on every tune whether
or not the caller asked for it — read off the decompiled radioservice in
apks/.

Not playing therefore has to be undone rather than skipped. tune takes an
andPlay flag and owns the outcome: true plays as before, false calls the
new pause (srcPauseRadio, transaction 28) as soon as the station is set.

The limitation left is the vendor's: pause mutes the tuner but does not
hand the audio focus back — the service only abandons it on loss, and for
AM/FM never — so whatever was playing before does not resume.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>

Author: malys

CHANGELOG.md

@@ -4,6 +4,29 @@ All notable changes to this project are documented here. Format follows
 [Keep a Changelog](https://keepachangelog.com/en/1.1.0/); versions follow
 [Semantic Versioning](https://semver.org/spec/v2.0.0.html).
 
+## [1.2.0] - 2026-08-22
+
+### Added
+
+- `SaicRadio.pause`, the vendor service's `srcPauseRadio` — the counterpart of `play`. It
+  mutes the tuner and marks the radio stopped; it does not hand the audio focus back, which
+  the vendor service only does when it loses it.
+
+### Changed
+
+- `SaicRadio.tune` takes an `andPlay` flag and is responsible for the outcome. 1.1.0 removed
+  the `srcPlayRadio` call and assumed that was enough to tune in silence; it is not. The
+  vendor's `tune` calls `AudioController.requestMuted(false)` itself, which requests the
+  audio focus and unmutes the tuner, so changing station always starts the radio. Not
+  playing is therefore something that has to be undone after the fact: `andPlay = false`
+  pauses the radio as soon as it is tuned. Callers must pass the flag — there is no default.
+
+### Known limitation
+
+- Tuning with `andPlay = false` leaves the radio holding the audio focus, silent. Whatever
+  was playing before does not resume: the vendor service exposes no way to give the focus
+  back for AM/FM, only for DAB scanning.
+
 ## [1.1.0] - 2026-08-22
 
 ### Changed

lib/src/main/java/com/evsuite/hardware/saic/SaicMedia.kt

@@ -18,6 +18,7 @@ object SaicRadio {
     private const val TX_TUNE = 8
     private const val TX_START_ACTIVITY = 26
     private const val TX_SRC_PLAY = 27
+    private const val TX_SRC_PAUSE = 28
 
     /** `RadioType`: 1 = AM, 2 = FM, 4 = DAB. */
     const val BAND_AM = 1
@@ -43,13 +44,28 @@ object SaicRadio {
         SaicAidl.callBoolean(service.binder(), DESCRIPTOR, TX_START_ACTIVITY) ?: false
 
     /**
-     * Tunes a frequency in kHz (FM 87500–108000), without touching the audio source.
+     * Silences the radio and marks it stopped — `srcPauseRadio`, the counterpart of [play].
      *
-     * Tuning and playing are kept apart because a caller may want the station set without
-     * the radio taking over what is currently playing; [play] is the explicit second step.
+     * It mutes the tuner rather than handing the audio focus back: the vendor service only
+     * abandons focus when it loses it, so whatever was playing before the radio took over
+     * does not resume on its own. Silence is the most this service offers.
      */
-    fun tune(band: Int, frequencyKhz: Int): Boolean =
-        SaicAidl.callVoid(service.binder(), DESCRIPTOR, TX_TUNE, band, frequencyKhz)
+    fun pause(): Boolean = SaicAidl.callVoid(service.binder(), DESCRIPTOR, TX_SRC_PAUSE)
+
+    /**
+     * Tunes a frequency in kHz (FM 87500–108000), playing it or leaving it silent.
+     *
+     * [andPlay] is not optional decoration on top of the tune: `tune` itself calls
+     * `AudioController.requestMuted(false)` inside the vendor service, which requests the
+     * audio focus and unmutes the tuner, so the radio starts playing whether or not anyone
+     * asked it to. A caller that wants the station set without the sound has to undo that,
+     * which is why the choice is made here rather than left to a second call the caller can
+     * forget: `andPlay = false` pauses the radio again as soon as it is tuned.
+     */
+    fun tune(band: Int, frequencyKhz: Int, andPlay: Boolean): Boolean {
+        if (!SaicAidl.callVoid(service.binder(), DESCRIPTOR, TX_TUNE, band, frequencyKhz)) return false
+        return if (andPlay) play() else pause()
+    }
 }
 
 /**