Add icons for eraser, select, and move tools

- Eraser: angled rectangle with dividing line (eraser tip)
- Select: dashed rectangle (marquee selection)
- Move: four-way arrow cross with arrowheads
All icons match the existing pen dot, line, and box icon style.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

app/src/main/kotlin/net/metacircular/engpad/ui/editor/Toolbar.kt

@@ -111,6 +111,79 @@ private fun BoxIcon(selected: Boolean) {
     }
 }
 
+/** Eraser icon — rectangle at an angle with a line underneath. */
+@Composable
+private fun EraserIcon(selected: Boolean) {
+    val color = if (selected) Color.White else Color.Black
+    Canvas(modifier = Modifier.size(18.dp)) {
+        val w = size.width
+        val h = size.height
+        val path = androidx.compose.ui.graphics.Path().apply {
+            // Angled eraser body
+            moveTo(w * 0.6f, h * 0.15f)
+            lineTo(w * 0.9f, h * 0.45f)
+            lineTo(w * 0.5f, h * 0.85f)
+            lineTo(w * 0.2f, h * 0.55f)
+            close()
+        }
+        drawPath(path, color = color, style = Stroke(width = 1.5f * density, cap = StrokeCap.Round))
+        // Dividing line between eraser tip and body
+        drawLine(color, Offset(w * 0.55f, h * 0.5f), Offset(w * 0.35f, h * 0.7f), 1.5f * density)
+    }
+}
+
+/** Select icon — dashed rectangle (marquee). */
+@Composable
+private fun SelectIcon(selected: Boolean) {
+    val color = if (selected) Color.White else Color.Black
+    Canvas(modifier = Modifier.size(18.dp)) {
+        val inset = 2f
+        drawRect(
+            color = color,
+            topLeft = Offset(inset, inset),
+            size = androidx.compose.ui.geometry.Size(size.width - inset * 2, size.height - inset * 2),
+            style = Stroke(
+                width = 1.5f * density,
+                pathEffect = androidx.compose.ui.graphics.PathEffect.dashPathEffect(
+                    floatArrayOf(4f * density, 3f * density), 0f,
+                ),
+            ),
+        )
+    }
+}
+
+/** Move icon — four-way arrow (cross with arrowheads). */
+@Composable
+private fun MoveIcon(selected: Boolean) {
+    val color = if (selected) Color.White else Color.Black
+    Canvas(modifier = Modifier.size(18.dp)) {
+        val w = size.width
+        val h = size.height
+        val cx = w / 2f
+        val cy = h / 2f
+        val arm = w * 0.35f
+        val head = w * 0.12f
+        val sw = 1.5f * density
+
+        // Cross lines
+        drawLine(color, Offset(cx, cy - arm), Offset(cx, cy + arm), sw, StrokeCap.Round)
+        drawLine(color, Offset(cx - arm, cy), Offset(cx + arm, cy), sw, StrokeCap.Round)
+
+        // Up arrow
+        drawLine(color, Offset(cx, cy - arm), Offset(cx - head, cy - arm + head), sw, StrokeCap.Round)
+        drawLine(color, Offset(cx, cy - arm), Offset(cx + head, cy - arm + head), sw, StrokeCap.Round)
+        // Down arrow
+        drawLine(color, Offset(cx, cy + arm), Offset(cx - head, cy + arm - head), sw, StrokeCap.Round)
+        drawLine(color, Offset(cx, cy + arm), Offset(cx + head, cy + arm - head), sw, StrokeCap.Round)
+        // Left arrow
+        drawLine(color, Offset(cx - arm, cy), Offset(cx - arm + head, cy - head), sw, StrokeCap.Round)
+        drawLine(color, Offset(cx - arm, cy), Offset(cx - arm + head, cy + head), sw, StrokeCap.Round)
+        // Right arrow
+        drawLine(color, Offset(cx + arm, cy), Offset(cx + arm - head, cy - head), sw, StrokeCap.Round)
+        drawLine(color, Offset(cx + arm, cy), Offset(cx + arm - head, cy + head), sw, StrokeCap.Round)
+    }
+}
+
 /** Undo arrow icon (curved left arrow). */
 @Composable
 private fun UndoIcon(enabled: Boolean) {
@@ -319,9 +392,15 @@ fun EditorToolbar(
             BoxIcon(currentTool == Tool.BOX)
         }
 
-        TextToolButton("Eraser", currentTool == Tool.ERASER, { onToolSelected(Tool.ERASER) })
+        ToolButton(selected = currentTool == Tool.ERASER, onClick = { onToolSelected(Tool.ERASER) }) {
-        TextToolButton("Select", currentTool == Tool.SELECT, { onToolSelected(Tool.SELECT) })
+            EraserIcon(currentTool == Tool.ERASER)
-        TextToolButton("Move", currentTool == Tool.MOVE, { onToolSelected(Tool.MOVE) })
+        }
+        ToolButton(selected = currentTool == Tool.SELECT, onClick = { onToolSelected(Tool.SELECT) }) {
+            SelectIcon(currentTool == Tool.SELECT)
+        }
+        ToolButton(selected = currentTool == Tool.MOVE, onClick = { onToolSelected(Tool.MOVE) }) {
+            MoveIcon(currentTool == Tool.MOVE)
+        }
 
         // Selection operations
         if (hasSelection || canPaste) {