fix(android): keep the accent button's width and corners

Moving the gradient onto a row inside the button lost both: the button's
own row hands its children no minimum size, so a fillMaxWidth button
painted the ramp only behind its label, and with square corners.

The gradient goes back on the button, and the 48dp touch-target padding
is taken by a box around it instead, with the button inside told not to
add its own. The primary button now matches the other buttons' 40dp
container at every width. The screenshots are re-recorded for it.

android/app/src/main/java/io/narl/protonstream/ui/theme/Accent.kt

@@ -2,18 +2,15 @@ package io.narl.protonstream.ui.theme
 
 import androidx.compose.foundation.Canvas
 import androidx.compose.foundation.background
-import androidx.compose.foundation.layout.Arrangement
+import androidx.compose.foundation.layout.Box
-import androidx.compose.foundation.layout.PaddingValues
-import androidx.compose.foundation.layout.Row
 import androidx.compose.foundation.layout.RowScope
-import androidx.compose.foundation.layout.defaultMinSize
 import androidx.compose.foundation.layout.fillMaxWidth
 import androidx.compose.foundation.layout.height
-import androidx.compose.foundation.layout.padding
 import androidx.compose.material3.Button
 import androidx.compose.material3.ButtonDefaults
 import androidx.compose.material3.ExperimentalMaterial3Api
 import androidx.compose.material3.FilledTonalButton
+import androidx.compose.material3.LocalMinimumInteractiveComponentSize
 import androidx.compose.material3.MaterialTheme
 import androidx.compose.material3.NavigationBarItemDefaults
 import androidx.compose.material3.NavigationDrawerItemDefaults
@@ -23,7 +20,9 @@ import androidx.compose.material3.adaptive.navigationsuite.NavigationSuiteDefaul
 import androidx.compose.material3.adaptive.navigationsuite.NavigationSuiteItemColors
 import androidx.compose.material3.SliderState
 import androidx.compose.material3.TextButton
+import androidx.compose.material3.minimumInteractiveComponentSize
 import androidx.compose.runtime.Composable
+import androidx.compose.runtime.CompositionLocalProvider
 import androidx.compose.runtime.remember
 import androidx.compose.ui.Alignment
 import androidx.compose.ui.Modifier
@@ -32,6 +31,7 @@ import androidx.compose.ui.geometry.Size
 import androidx.compose.ui.graphics.Brush
 import androidx.compose.ui.graphics.Color
 import androidx.compose.ui.graphics.SolidColor
+import androidx.compose.ui.unit.Dp
 import androidx.compose.ui.unit.dp
 
 /**
@@ -73,29 +73,30 @@ internal fun AccentButton(
     enabled: Boolean = true,
     content: @Composable RowScope.() -> Unit,
 ) {
-    // The ramp is painted inside the container, not on `modifier`: the button
+    val shape = MaterialTheme.shapes.small
-    // pads itself out to the 48dp minimum touch target, and a background on
+    // The button pads itself out to the 48dp minimum touch target, and a
-    // the outer modifier fills that whole target — 8dp taller than the 40dp
+    // background on its modifier fills that whole target — 8dp taller than
-    // container every other button draws, so it stood out beside them.
+    // the 40dp container every other button draws. So the padding is taken
-    Button(
+    // here, outside the ramp, and the button inside is told not to add its
-        onClick = onClick,
+    // own. The box hands its size down, so a `fillMaxWidth` still reaches it.
-        modifier = modifier,
+    Box(
-        enabled = enabled,
+        modifier.minimumInteractiveComponentSize(),
-        shape = MaterialTheme.shapes.small,
+        contentAlignment = Alignment.Center,
-        colors = ButtonDefaults.buttonColors(containerColor = Color.Transparent),
+        propagateMinConstraints = true,
-        contentPadding = PaddingValues(0.dp),
     ) {
-        Row(
+        CompositionLocalProvider(LocalMinimumInteractiveComponentSize provides Dp.Unspecified) {
-            // Only while it is live: a disabled button keeps Material's flat
+            Button(
-            // disabled container, because a greyed control that still wears
+                onClick = onClick,
-            // the one strong colour in the window reads as pressable.
+                // Only while it is live: a disabled button keeps Material's flat
-            modifier = (if (enabled) Modifier.background(accentBrush()) else Modifier)
+                // disabled container, because a greyed control that still wears the
-                .defaultMinSize(ButtonDefaults.MinWidth, ButtonDefaults.MinHeight)
+                // one strong colour in the window reads as pressable.
-                .padding(ButtonDefaults.ContentPadding),
+                modifier = if (enabled) Modifier.background(accentBrush(), shape) else Modifier,
-            horizontalArrangement = Arrangement.Center,
+                enabled = enabled,
-            verticalAlignment = Alignment.CenterVertically,
+                shape = shape,
-            content = content,
+                colors = ButtonDefaults.buttonColors(containerColor = Color.Transparent),
-        )
+                content = content,
+            )
+        }
     }
 }