feat(import): RennmausPro-III-Backup-Importer (analyze+execute, Dedup, Fotos)

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

GerbilManagerWebAPI/Import/Rpro3/Rpro3Guid.cs

@@ -0,0 +1,31 @@
+using System.Security.Cryptography;
+using System.Text;
+
+namespace GerbilManagerWebAPI.Import.Rpro3
+{
+    /// <summary>
+    /// Deterministische GUIDs aus stabilen RPRO3-Schlüsseln (analog zum Python `generate_guid`-Muster).
+    /// Gleicher Schlüssel → gleiche GUID über Re-Imports hinweg → idempotent.
+    /// MD5-basiert (Namespace-Präfix vermeidet Kollisionen mit anderen Entitätstypen).
+    /// </summary>
+    public static class Rpro3Guid
+    {
+        public const string ImportSource = "RennmausPro III";
+
+        public static Guid For(string @namespace, string key)
+        {
+            var bytes = MD5.HashData(Encoding.UTF8.GetBytes($"rpro3:{@namespace}:{key}"));
+            return new Guid(bytes);
+        }
+
+        public static Guid Gerbil(string clusterRootRid) => For("gerbil", clusterRootRid);
+        public static Guid Litter(int wurfId) => For("litter", wurfId.ToString());
+        public static Guid Contact(string ns, int id) => For("contact", $"{ns}:{id}");
+        public static Guid Health(string tid, string disc, int seq) => For("health", $"{tid}:{seq}:{disc}");
+        public static Guid Weight(string tid, int seq) => For("weight", $"{tid}:{seq}");
+
+        /// <summary>Stabiler ExternalRef-Wert (Gerbil/Litter Idempotenzschlüssel, UNIQUE-Spalte).</summary>
+        public static string GerbilRef(string rootRid) => $"rpro3:{rootRid}";
+        public static string LitterRef(int wurfId) => $"rpro3-wurf:{wurfId}";
+    }
+}