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/shell/LeftNav.tsx

@@ -6,13 +6,12 @@ import {
   Activity,
   Bookmark,
   Boxes,
-  Settings,
   Coins,
   type LucideIcon,
 } from "lucide-react";
 import { cn } from "../ui";
 
-export type ViewKey = "home" | "studio" | "kb" | "report" | "runs" | "memory" | "usage" | "market" | "admin";
+export type ViewKey = "home" | "studio" | "kb" | "report" | "runs" | "memory" | "usage" | "market";
 
 interface Item {
   key: ViewKey;
@@ -30,8 +29,7 @@ const ITEMS: Item[] = [
   { key: "runs", label: "运行", icon: Activity, group: "RUN", ready: true },
   { key: "memory", label: "记忆", icon: Bookmark, group: "MANAGE", ready: true },
   { key: "usage", label: "用量", icon: Coins, group: "MANAGE", ready: true },
-  { key: "market", label: "市场", icon: Boxes, group: "MANAGE" },
-  { key: "admin", label: "管理", icon: Settings, group: "MANAGE" },
+  { key: "market", label: "市场", icon: Boxes, group: "MANAGE", ready: false },
 ];
 
 // 左导航：深色，激活态紫色高亮 + 左侧光条，描线图标。

sundynix-desktop/frontend/src/shell/TopBar.tsx

@@ -130,17 +130,6 @@ export function TopBar({ user, tenant, tenants = [], onSwitchTenant, space, spac
         </div>
         <span className="brand-gradient text-sm font-semibold">sundynix-agentix</span>
       </div>
-      <div className="relative" style={NODRAG}>
-        <select
-          className="appearance-none rounded-md border border-line bg-ink-800 py-1 pl-2.5 pr-7 text-xs text-slate-300 focus:border-brand focus:outline-none"
-          defaultValue="通用版"
-        >
-          <option>通用版</option>
-          <option>法律版</option>
-          <option>医疗版</option>
-        </select>
-        <ChevronDown className="pointer-events-none absolute right-2 top-1/2 h-3.5 w-3.5 -translate-y-1/2 text-slate-500" />
-      </div>
       <button
         onClick={onCommand}
         style={NODRAG}