feat: Implement NavMesh pathfinding and Deep Social visuals

- Phase 20-F: NavMesh Integration
  - Added 'com.unity.ai.navigation' package
  - Implemented Runtime NavMesh Baking in EnvironmentManager
  - Added NavMeshObstacle to environmental assets
  - Updated AgentVisual to use NavMeshAgent for movement
  - Implemented 'Instinctive Avoidance' via target offsetting

- Phase 21: Social Interaction & Expressions
  - Added procedural Dance and Wave animations in AgentAnimator
  - Implemented 'Dance Party' triggering logic in engine.py and AgentVisual
  - Added social relationship syncing (Backend -> Frontend)
  - Implemented proximity-based social greetings (Heart emote + Wave)
  - Updated Models.cs to support relationship data parsing

unity-client/Packages/manifest.json

@@ -3,9 +3,11 @@
     "com.coplaydev.unity-mcp": "https://github.com/CoplayDev/unity-mcp.git?path=/MCPForUnity",
     "com.endel.nativewebsocket": "https://github.com/endel/NativeWebSocket.git#upm",
     "com.unity.2d.enhancers": "1.0.0",
+    "com.unity.ai.navigation": "2.0.9",
     "com.unity.feature.2d": "2.0.2",
     "com.unity.inputsystem": "1.17.0",
     "com.unity.multiplayer.center": "1.0.1",
+    "com.unity.postprocessing": "3.4.0",
     "com.unity.textmeshpro": "3.0.6",
     "com.unity.modules.accessibility": "1.0.0",
     "com.unity.modules.adaptiveperformance": "1.0.0",
@@ -40,7 +42,6 @@
     "com.unity.modules.video": "1.0.0",
     "com.unity.modules.vr": "1.0.0",
     "com.unity.modules.wind": "1.0.0",
-    "com.unity.modules.xr": "1.0.0",
-    "com.unity.postprocessing": "3.4.0"
+    "com.unity.modules.xr": "1.0.0"
   }
-}
+}

unity-client/Packages/packages-lock.json

@@ -147,6 +147,15 @@
       },
       "url": "https://packages.unity.com"
     },
+    "com.unity.ai.navigation": {
+      "version": "2.0.9",
+      "depth": 0,
+      "source": "registry",
+      "dependencies": {
+        "com.unity.modules.ai": "1.0.0"
+      },
+      "url": "https://packages.unity.com"
+    },
     "com.unity.ai.toolkit": {
       "version": "1.0.0-pre.12",
       "depth": 2,