refactor: extract grid abstraction for reuse

internal/position/position_test.go

@@ -0,0 +1,22 @@
+package position_test
+
+import (
+	"testing"
+
+	"github.com/StevanFreeborn/advent-of-code-2025/internal/position"
+)
+
+func TestFrom(t *testing.T) {
+	row := 3
+	column := 5
+
+	pos := position.From(row, column)
+
+	if pos.Row() != row {
+		t.Errorf("expected row to be %d, got %d", row, pos.Row())
+	}
+
+	if pos.Column() != column {
+		t.Errorf("expected column to be %d, got %d", column, pos.Column())
+	}
+}