Phase 0.1: Resource extraction pipeline

- Add OrderedDictionary JSON converter for round-trip support
- Add ObjLoadRaw() for GDI+-free binary resource loading
- Simplify Ser.cs JSON methods (consistent settings, JsonConvert API)
- Create SlaveMatrix.Extract CLI tool for resource extraction
- Manual export walks Obj/Difs/Dif/Pars/Par hierarchy
- Exports all 13 Obj resources to structured JSON with shape data
- Update .gitignore for build artifacts and extraction output

2DGAMELIB/_2DGAMELIB/OrderedDictionaryConverter.cs

@@ -0,0 +1,47 @@
+using System;
+using System.Collections.Generic;
+using Newtonsoft.Json;
+using Newtonsoft.Json.Linq;
+
+namespace _2DGAMELIB
+{
+    public class OrderedDictionaryConverter<T1, T2> : JsonConverter<OrderedDictionary<T1, T2>>
+        where T1 : notnull
+    {
+        public override OrderedDictionary<T1, T2> ReadJson(JsonReader reader, Type objectType, OrderedDictionary<T1, T2> existingValue, bool hasExistingValue, JsonSerializer serializer)
+        {
+            var dict = new OrderedDictionary<T1, T2>();
+
+            if (reader.TokenType == JsonToken.Null)
+                return dict;
+
+            var array = JArray.Load(reader);
+
+            foreach (var item in array)
+            {
+                var key = item["Key"].ToObject<T1>(serializer);
+                var value = item["Value"].ToObject<T2>(serializer);
+                dict.Add(key, value);
+            }
+
+            return dict;
+        }
+
+        public override void WriteJson(JsonWriter writer, OrderedDictionary<T1, T2> value, JsonSerializer serializer)
+        {
+            writer.WriteStartArray();
+
+            foreach (var key in value.Keys)
+            {
+                writer.WriteStartObject();
+                writer.WritePropertyName("Key");
+                serializer.Serialize(writer, key);
+                writer.WritePropertyName("Value");
+                serializer.Serialize(writer, value[key]);
+                writer.WriteEndObject();
+            }
+
+            writer.WriteEndArray();
+        }
+    }
+}