settings: clamp the preamp and make the dialog test assert

Review follow-ups.

- The snap clamped nothing, so an out-of-range stored value would show a
  decibel label the slider cannot reach: clamps now live in the snap
  rather than duplicated in the step.
- The screenshot test only rendered the dialog without asserting it
  opened, so deleting the row's click would have left it passing while
  the capture showed the plain list. It now requires the dialog's Reset.
- "Adjust level on top of the ReplayGain" was not grammatical, and the
  mode prompt claimed the server normalises when it only supplies the
  tags.
- Drop a test assertion that restated the production formula.

app/src/main/kotlin/com/subtracks/ui/settings/ReplayGainControls.kt

@@ -15,14 +15,14 @@ internal val REPLAY_GAIN_PREAMP_STEPS =
 // Compose Material 3's Slider snaps in pixel space and converts back, so the value it reports is
 // near, but not on, the grid it was configured with (for example -0.99999905 for -1.0). Snap before
 // showing or storing it.
-internal fun snapReplayGainPreampDb(value: Float): Float = (value / REPLAY_GAIN_PREAMP_STEP_DB).roundToInt() * REPLAY_GAIN_PREAMP_STEP_DB
+internal fun snapReplayGainPreampDb(value: Float): Float =
+    ((value / REPLAY_GAIN_PREAMP_STEP_DB).roundToInt() * REPLAY_GAIN_PREAMP_STEP_DB)
+        .coerceIn(MIN_REPLAY_GAIN_PREAMP_DB, MAX_REPLAY_GAIN_PREAMP_DB)
 
 internal fun stepReplayGainPreampDb(
     value: Float,
     steps: Int,
-): Float =
-    snapReplayGainPreampDb(value + steps * REPLAY_GAIN_PREAMP_STEP_DB)
-        .coerceIn(MIN_REPLAY_GAIN_PREAMP_DB, MAX_REPLAY_GAIN_PREAMP_DB)
+): Float = snapReplayGainPreampDb(value + steps * REPLAY_GAIN_PREAMP_STEP_DB)
 
 internal fun replayGainModeLabel(
     resources: Resources,

app/src/main/res/values/strings.xml

@@ -79,11 +79,11 @@
     <string name="settings_replay_gain_mode_track">Track gain</string>
     <string name="settings_replay_gain_preamp_decrease">Lower preamp</string>
     <string name="settings_replay_gain_preamp_increase">Raise preamp</string>
-    <string name="settings_replay_gain_preamp_prompt">Adjust level on top of the ReplayGain</string>
+    <string name="settings_replay_gain_preamp_prompt">Extra level on top of ReplayGain</string>
     <string name="settings_replay_gain_preamp_reset">Reset</string>
     <string name="settings_replay_gain_preamp_title">Preamp</string>
     <string name="settings_replay_gain_preamp_value">%1$s dB</string>
-    <string name="settings_replay_gain_prompt">Normalise loudness with the server\'s ReplayGain</string>
+    <string name="settings_replay_gain_prompt">Normalise loudness using the ReplayGain tags from the server</string>
     <string name="settings_replay_gain_title">ReplayGain</string>
     <string name="settings_network_name">Network</string>
     <string name="settings_network_options_max_bitrate_mobile_title">Stream quality: Mobile</string>

app/src/test/kotlin/com/subtracks/ui/AppScreenshotTest.kt

@@ -355,6 +355,7 @@ class AppScreenshotTest {
         composeRule.onNode(hasScrollAction()).performScrollToNode(hasText("Preamp"))
         composeRule.onAllNodesWithText("Preamp")[0].performClick()
         composeRule.waitForIdle()
+        composeRule.onAllNodesWithText("Reset").assertCountEquals(1)
         composeRule.onRoot().captureRoboImage("src/test/screenshots/replay_gain_preamp.png")
     }
 

app/src/test/kotlin/com/subtracks/ui/settings/ReplayGainControlsTest.kt

@@ -30,7 +30,6 @@ class ReplayGainControlsTest {
 
     @Test
     fun theSliderHasOneStepPerHalfDecibel() {
-        assertEquals(60, ((MAX_REPLAY_GAIN_PREAMP_DB - MIN_REPLAY_GAIN_PREAMP_DB) / REPLAY_GAIN_PREAMP_STEP_DB).toInt())
         assertEquals(59, REPLAY_GAIN_PREAMP_STEPS)
     }
 
@@ -51,4 +50,10 @@ class ReplayGainControlsTest {
         assertEquals(MAX_REPLAY_GAIN_PREAMP_DB, snapReplayGainPreampDb(14.9f), 0f)
         assertEquals(MIN_REPLAY_GAIN_PREAMP_DB, snapReplayGainPreampDb(-14.9f), 0f)
     }
+
+    @Test
+    fun thePreampIsClampedToItsRange() {
+        assertEquals(MAX_REPLAY_GAIN_PREAMP_DB, snapReplayGainPreampDb(20f), 0f)
+        assertEquals(MIN_REPLAY_GAIN_PREAMP_DB, snapReplayGainPreampDb(-20f), 0f)
+    }
 }