feat(web): #66 AI sprite for xiaoai + resolveKey for xiaoqian/xiaohou

- xiaoai resolves to AI-generated spritesheet (agent-xiaoai_ai.png)
- Add xiaoqian/xiaohou name matching in resolveKey
- Fix generate_jimeng_spritesheet.py NVM sourcing

Closes #66

Author: Ubuntu

packages/web/public/sprites/agent-xiaoqian_ai.png

@@ -19,6 +19,7 @@
 MCPORTER_BIN = "/home/ubuntu/.local/share/pnpm/mcporter"
 NODE_PATH = "/home/ubuntu/.local/share/pnpm/global/5/.pnpm/mcporter@0.7.3_hono@4.11.7/node_modules"
 BUN_BIN = "/home/ubuntu/.bun/bin/bun"
+NVM_SHELL = "/home/ubuntu/.nvm/nvm.sh"
 
 TARGET_W, TARGET_H = 256, 192
 FRAME_W, FRAME_H = 64, 64
@@ -36,6 +37,7 @@ def call_jimeng(prompt: str, aspect_ratio: str = "3:2") -> list[str]:
         "--output", "text"
     ]
     env = os.environ.copy()
+    env["NVM_DIR"] = "/home/ubuntu/.nvm"
     env["NODE_PATH"] = NODE_PATH
 
     result = subprocess.run(

packages/web/scripts/generate_jimeng_spritesheet.py

@@ -11,13 +11,11 @@ import { StatusBubble } from './SceneDecorations';
 // Sprite sheet registry
 // ──────────────────────────────────────────────
 const SPRITE_SHEETS: Record<string, string> = {
-  xiaoai:   '/sprites/agent-xiaoai.png',
+  xiaoai:   '/sprites/agent-xiaoai_ai.png',
   xiaochan: '/sprites/agent-xiaochan.png',
   xiaokai:  '/sprites/agent-xiaokai.png',
   xiaoqian: '/sprites/agent-xiaoqian-emoji.png',
   xiaohou:  '/sprites/agent-xiaohou-emoji.png',
-  xiaoai_ai:  '/sprites/agent-xiaoai_ai.png',
-  xiaohou_ai: '/sprites/agent-xiaohou_ai.png',
 };
 
 const FALLBACK_POOL = Object.values(SPRITE_SHEETS);
@@ -200,6 +198,8 @@ export class AgentSprite {
     if (name.includes('爱')) return 'xiaoai';
     if (name.includes('产') || name.includes('chan')) return 'xiaochan';
     if (name.includes('开') || name.includes('kai'))  return 'xiaokai';
+    if (name.includes('后') || name.includes('hou'))   return 'xiaohou';
+    if (name.includes('前') || name.includes('qian')) return 'xiaoqian';
     return agent.id.toLowerCase();
   }