fix(ui): improve starred icon visibility in articles list

[blizzardOfAce]

Fixes: #1192

This PR improves the visibility of the "starred icon" in the article list.

What this PR changes

• The icon now scales dynamically based on the current text size, so it respects user font scaling.
• Color is updated to a higher-contrast onSurface with slight alpha.

Before	After

Code changes:

@Composable
fun StarredIcon(modifier: Modifier = Modifier) {
+    val fontSize = LocalTextStyle.current.fontSize
+    val iconSize = with(LocalDensity.current) { fontSize.toDp() }

    Icon(
        modifier = modifier
-            .size(16.dp)
+            .size(iconSize) //  scales with font size
            .padding(end = 2.dp),
        imageVector = Icons.Rounded.Star,
        contentDescription = stringResource(R.string.starred),
-        tint = Color.Gray,
+        tint = MaterialTheme.colorScheme
+            .onSurface
+            .copy(alpha = 0.7f), //  better visibility (theme-adaptive)
    )
}

[Ashinch]

It looks good.