feat(db): add TutorialPresents seed list

SVSim.Database/SeedData/TutorialPresents.cs

@@ -0,0 +1,30 @@
+namespace SVSim.Database.SeedData;
+
+/// <summary>
+/// The five tutorial gifts every fresh viewer is given at signup. Mirrors the prod-shaped
+/// gift inbox — these rows are indistinguishable from server-issued gifts at read time
+/// except for the Source tag.
+///
+/// Moved here from the old static <c>GiftController.TutorialGifts</c> PresentDto array;
+/// now insert-only data, not DTOs, so signup writes go straight into ViewerPresent rows
+/// without round-tripping through wire types.
+/// </summary>
+public static class TutorialPresents
+{
+    public record Spec(
+        string PresentId,
+        int RewardType,
+        long RewardDetailId,
+        long RewardCount,
+        int? ItemType,
+        string Message);
+
+    public static readonly IReadOnlyList<Spec> All = new[]
+    {
+        new Spec("71478626", 1, 0,     400, null, "For completing the tutorial"),  // Crystal
+        new Spec("71478627", 9, 0,     100, null, "For completing the tutorial"),  // Rupy
+        new Spec("71478628", 4, 1,       3, 1,    "For completing the tutorial"),  // Item type=1, x3 of item 1
+        new Spec("71478629", 4, 80001,  40, 2,    "For completing the tutorial"),  // Pack ticket 80001 x40
+        new Spec("71478630", 4, 90001,   1, 2,    "For completing the tutorial"),  // Pack ticket 90001 x1
+    };
+}