refactor(desktop): 清理死 UI / 假功能(P0 完善)

让桌面端只暴露"真的能用"的东西,提升完成度观感、避免误导:
- 删顶栏假"版本选择器"(通用版/法律版/医疗版)——死 defaultValue、无 onChange
- 删「管理」导航项 + 其占位页/命令——内容是 admin 控制台的事(租户/计费/护栏/模型),
  违背 desktop/admin 产品边界,留着只是让用户点了扑空
- 「市场·Packs」标记 ready:false(规划中徽标 + 标题标注),不再伪装成已就绪功能;
  移除其命令面板项(命令面板只列真实可达目的地)
- Agent 节点模型选项去掉假的"占位 Pool/ollama:qwen/vllm:custom",改由已登记模型
  运行时填充(无模型时显示"（无，先创建）"而非可误选的假项);默认 model 置空

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

sundynix-desktop/frontend/src/studio/nodeCatalog.ts

@@ -63,12 +63,12 @@ export const NODE_KINDS: Record<string, NodeKind> = {
     badge: "bg-violet-100 text-violet-700",
     desc: "调模型生成",
     fields: [
-      { key: "model", label: "模型", type: "select", options: ["占位 Pool", "ollama:qwen", "vllm:custom"], required: true },
+      { key: "model", label: "模型", type: "select", options: [], required: true }, // 运行时由已登记模型填充(dynamicOptions.model)
       { key: "system", label: "系统提示词", type: "textarea", placeholder: "你是…" },
       { key: "temperature", label: "温度", type: "number" },
       { key: "autonomous", label: "自主工具 (ReAct)", type: "checkbox" },
     ],
-    defaults: { model: "占位 Pool", system: "", temperature: 0.7, autonomous: false },
+    defaults: { model: "", system: "", temperature: 0.7, autonomous: false },
   },
   coordinator: {
     kind: "coordinator",