feat(unity): enhance visual effects and animations

- Add cloud system with procedural sprites and parallax movement
- Add tree swaying animation for palm trees
- Improve agent breathing with squash & stretch animation
- Add jump animation routine for agent reactions
- Add custom CartoonWater shader support
- Add SetupVisuals editor tool and GlobalProfile asset
- Lower speech bubble alpha for glass effect

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

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

unity-client/Assets/Scripts/UIManager.cs

@@ -164,7 +164,7 @@ namespace TheIsland.UI
             topBar.offsetMax = new Vector2(-10, -10);
 
             var topBarImg = topBar.gameObject.AddComponent<Image>();
-            topBarImg.color = new Color(0, 0, 0, 0.7f);
+            topBarImg.color = new Color(0, 0, 0, 0.0f); // 透明顶部栏
 
             // Connection Status (Left)
             _connectionStatus = CreateText(topBar, "ConnectionStatus", "● Disconnected",
@@ -205,7 +205,7 @@ namespace TheIsland.UI
             bottomBar.offsetMax = new Vector2(-10, 70);
 
             var bottomBarImg = bottomBar.gameObject.AddComponent<Image>();
-            bottomBarImg.color = new Color(0, 0, 0, 0.7f);
+            bottomBarImg.color = new Color(0, 0, 0, 0.2f); // 低透明度底部栏
 
             // Command Input
             var inputObj = new GameObject("CommandInput");