SEED-REW: rename ColorVariety 'Pink Eyed White (PEW)' to 'REW'

Single UpdateData migration for ID 00000000-...-0001 (sortOrder 0).
Name-only rename, genotype/ID/FK unchanged — no drift risk.
Matches colorVarietySeed.backend.json after GEN-4c (main 3aa9ac9).

165/165 tests, ef has-pending=No.

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

GerbilManagerWebAPI/Migrations/20260606231220_RenameREW.cs

@@ -0,0 +1,33 @@
+using System;
+using Microsoft.EntityFrameworkCore.Migrations;
+
+#nullable disable
+
+namespace GerbilManagerWebAPI.Migrations
+{
+    /// <inheritdoc />
+    public partial class RenameREW : Migration
+    {
+        /// <inheritdoc />
+        protected override void Up(MigrationBuilder migrationBuilder)
+        {
+            migrationBuilder.UpdateData(
+                table: "ColorVarieties",
+                keyColumn: "Id",
+                keyValue: new Guid("00000000-0000-0000-0000-000000000001"),
+                column: "Name",
+                value: "REW");
+        }
+
+        /// <inheritdoc />
+        protected override void Down(MigrationBuilder migrationBuilder)
+        {
+            migrationBuilder.UpdateData(
+                table: "ColorVarieties",
+                keyColumn: "Id",
+                keyValue: new Guid("00000000-0000-0000-0000-000000000001"),
+                column: "Name",
+                value: "Pink Eyed White (PEW)");
+        }
+    }
+}

GerbilManagerWebAPI/Migrations/ApplicationContextModelSnapshot.cs

@@ -216,7 +216,7 @@ namespace GerbilManagerWebAPI.Migrations
                         {
                             Id = new Guid("00000000-0000-0000-0000-000000000001"),
                             CanonicalGenotype = "AA chch DD EE GG pp spsp rere",
-                            Name = "Pink Eyed White (PEW)",
+                            Name = "REW",
                             SortOrder = 0
                         },
                         new