ImportScreen: fade gradient indicates more content below

derivedStateOf tracks scrollState.value < maxValue. When not at
bottom, a 48dp white-to-transparent gradient overlays the bottom
of the scroll area. Disappears when fully scrolled.

src/main/kotlin/com/bolenpad/photophetch/ui/ImportScreen.kt

@@ -9,6 +9,9 @@ import androidx.compose.material3.*
 import androidx.compose.runtime.*
 import androidx.compose.ui.Alignment
 import androidx.compose.ui.Modifier
+import androidx.compose.ui.draw.drawWithContent
+import androidx.compose.ui.graphics.Brush
+import androidx.compose.ui.graphics.Color
 import androidx.compose.ui.text.font.FontWeight
 import androidx.compose.ui.unit.dp
 import com.bolenpad.photophetch.util.StagingPath
@@ -43,11 +46,15 @@ fun ImportScreen(state: AppState) {
 
         HorizontalDivider()
 
-        // ── Scrollable body ──────────────────────────────────────────────────
+        // ── Scrollable body with bottom fade ────────────────────────────────
+        val scrollState = rememberScrollState()
+        val showFade by remember { derivedStateOf { scrollState.value < scrollState.maxValue } }
+
+        Box(modifier = Modifier.weight(1f)) {
             Column(
                 modifier = Modifier
-                .weight(1f)
-                .verticalScroll(rememberScrollState())
+                    .fillMaxSize()
+                    .verticalScroll(scrollState)
                     .padding(horizontal = 32.dp, vertical = 20.dp),
                 verticalArrangement = Arrangement.spacedBy(20.dp),
             ) {
@@ -134,7 +141,28 @@ fun ImportScreen(state: AppState) {
 
             // Extra bottom padding so last item isn't flush against the button
             Spacer(Modifier.height(8.dp))
+        } // end scroll Column
+
+        // Fade gradient — visible when not scrolled to bottom
+        if (showFade) {
+            Box(
+                modifier = Modifier
+                    .fillMaxWidth()
+                    .height(48.dp)
+                    .align(Alignment.BottomCenter)
+                    .drawWithContent {
+                        drawContent()
+                        drawRect(
+                            brush = Brush.verticalGradient(
+                                colors = listOf(Color.Transparent, Color.White),
+                                startY = 0f,
+                                endY = size.height,
+                            )
+                        )
                     }
+            )
+        }
+        } // end Box
 
         // ── Pinned bottom button ─────────────────────────────────────────────
         HorizontalDivider()