feat: implement survival, crafting, memory, and social systems

- Phase 13: Autonomous Agency - agents now have actions and locations
- Phase 15: Sickness mechanics with immunity and weather effects
- Phase 16: Crafting system (medicine from herbs)
- Phase 17-A: Resource scarcity with tree fruit regeneration
- Phase 17-B: Social roles (leader, follower, loner) with clique behavior
- Phase 17-C: Random events support
- Add AgentMemory model for long-term agent memory storage
- Add memory_service for managing agent memories
- Update Unity client models and event handlers

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

unity-client/Assets/Scripts/Visual/EnvironmentManager.cs

@@ -56,7 +56,6 @@ namespace TheIsland.Visual
         [SerializeField] private Color waterShallowColor = new Color(0.3f, 0.8f, 0.9f, 0.8f);
         [SerializeField] private Color waterDeepColor = new Color(0.1f, 0.4f, 0.6f, 0.9f);
         [SerializeField] private float waveSpeed = 0.5f;
-        [SerializeField] private float waveAmplitude = 0.1f;
         [SerializeField] private Material customWaterMaterial; // Custom shader support
         #endregion