Record FAB paints with accent (primary); Material3 default primaryContainer muted it

- Theme: derive primaryContainer from accent in both schemes (other container-tinted surfaces follow accent now)
- Home FAB: explicit containerColor=primary so button color == accent_color exactly
- Settings: hide 'Reset to default' on non-editable settings (App version showed it and threw 'not editable')

android/app/src/main/java/com/shonar/ui/home/HomeScreen.kt

@@ -122,6 +122,8 @@ fun HomeScreen(
                         }
                     }
                 },
+                containerColor = MaterialTheme.colorScheme.primary,
+                contentColor = MaterialTheme.colorScheme.onPrimary,
                 icon = { Icon(Icons.Filled.Mic, contentDescription = null) },
                 text = {
                     Text(if (recorderState.phase == com.shonar.recording.RecordingSnapshot.Phase.IDLE) "Record" else "Stop")

android/app/src/main/java/com/shonar/ui/settings/SettingsScreen.kt

@@ -257,10 +257,12 @@ private fun Control(
                     }.isFailure,
                 supportingText = {
                     Row {
+                        if (def.editable) {
                             TextButton(onClick = onReset, contentPadding = androidx.compose.foundation.layout.PaddingValues(0.dp)) {
                                 Text("Reset to default")
                             }
                         }
+                    }
                 },
                 modifier = Modifier.fillMaxWidth(),
             )
@@ -378,10 +380,12 @@ private fun Control(
                     )
                 }
             }
+            if (def.editable) {
                 TextButton(onClick = onReset) { Text("Reset") }
             }
         }
     }
+}
 
 private fun encodeString(s: String): String =
     JsonPrimitive(s).toString()

android/app/src/main/java/com/shonar/ui/theme/Theme.kt

@@ -12,6 +12,7 @@ import androidx.compose.runtime.mutableStateOf
 import androidx.compose.runtime.remember
 import androidx.compose.runtime.setValue
 import androidx.compose.ui.graphics.Color
+import androidx.compose.ui.graphics.lerp
 import androidx.compose.ui.graphics.luminance
 import com.shonar.settings.SettingsManager
 
@@ -27,6 +28,10 @@ private fun schemeFor(accent: Color, dark: Boolean) = if (dark) {
         primary = accent,
         onPrimary = if (accent.luminance() > 0.4) Ink else Color.White,
         secondary = accent.copy(alpha = 0.8f),
+        // FABs (the mic button) paint with primaryContainer, not primary —
+        // derive it from the accent so accent_color actually changes them.
+        primaryContainer = lerp(NavySurface, accent, 0.35f),
+        onPrimaryContainer = if (accent.luminance() > 0.4) Ink else Color.White,
         background = DeepNavy,
         surface = NavySurface,
         onBackground = Color(0xFFE6EDF3),
@@ -37,6 +42,8 @@ private fun schemeFor(accent: Color, dark: Boolean) = if (dark) {
         primary = accent,
         onPrimary = if (accent.luminance() > 0.4) Ink else Color.White,
         secondary = accent.copy(alpha = 0.8f),
+        primaryContainer = lerp(Color.White, accent, 0.35f),
+        onPrimaryContainer = if (accent.luminance() > 0.4) Ink else Color.White,
     )
 }