Add formal enemies, remaining formal partners and synthesized UI SFX

- UI SFX v3: procedurally synthesized one-shots (Tools/synth_ui_sfx.py) wired to
  buttons, rewards, errors and red dots via UiSfx, gated by the SFX setting.
- Five formal enemies (Hornlet, Dashlet, Shellhorn, HornCaptain, GreatHorn):
  Hunyuan 50k -> 2000-tri XPbr, DGXA TokenRig, Idle/Walk/Attack, nested per type
  in PrototypeArena; PrototypeBattle.Enemy gains presentation-only Moving/Strikes.
- Formal partners for all ten pets in the arena and portraits, including new
  VineSprite, ThunderLeopard and TideWhale.
- Pipeline fixes: reject local TokenRig fallback, drop loose mesh islands,
  configurable Unity run_script timeout, companion static stage.
- Also includes concurrent work from another tool in this working tree
  (FlameLion, enemy combat FX, challenge mode, home explorer, server updates).
- Resources registered in Doc/ResDesc_*.md; verified on isolated :18081.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

ProjectDesign.md

@@ -376,6 +376,7 @@ BootContext（壳 → 热更）至少传递：
 | [`ResourceCreate.md`](ResourceCreate.md) | 图、3D、减面烘焙生成方式 |
 | [`Doc/ResDesc.md`](Doc/ResDesc.md) | 资源登记索引 |
 | [`UNITY-GUIDE.md`](UNITY-GUIDE.md) | Agent 操作 Unity 规范 |
+| [`Doc/Design/Combat/SkillSystem.md`](Doc/Design/Combat/SkillSystem.md) | 关卡技能系统设计：逻辑行为、动作/特效/音效组合、固定tick事件、服务端结算与TangoFlux制作流程；当前为设计及配置契约，尚未切换运行时 |
 | [`Agents.md`](Agents.md) | 项目可读摘要 |
 
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