桌面应用图标替换为 B-brackets 设计（深藏青 + 白/蓝花括号）

- icon.svg 取自 opsx-icon-options/api/B-brackets.svg，全套光栅重生成：
  icon.icns（iconutil）、icon.ico（PNG-in-ICO 6 尺寸）、16-1024 PNG、Windows Square*/StoreLogo
- 替换 Tauri 脚手架默认五角星图标；GUI 重启实测 Dock 图标已生效
- 服务全量重启：server 8787（官网/文档 200）+ web 5173 + 桌面 GUI

apps/web/public/design-proxy-layers.html

@@ -0,0 +1,57 @@
+<!doctype html>
+<html lang="zh-CN">
+<head>
+  <meta charset="utf-8" />
+  <title>OpsxAPI · 路径 B 代理错误分层验收</title>
+  <style>
+    :root { --bg:#0f1419; --text:#e7ecf3; --muted:#8b98a8; --border:#2a3441; --btn:#1e2733; }
+    * { box-sizing: border-box; }
+    body { margin:0; font:13px/1.45 ui-sans-serif,system-ui,sans-serif; background:var(--bg); color:var(--text); padding:24px; }
+    h1 { font-size:16px; margin:0 0 4px; }
+    .sub { color:var(--muted); margin-bottom:20px; }
+    .stack { display:flex; flex-direction:column; gap:14px; max-width:720px; }
+    .banner { border-radius:10px; border:1px solid; padding:12px 14px; }
+    .row { display:flex; align-items:center; gap:8px; margin-bottom:6px; }
+    .pill { display:inline-flex; align-items:center; border-radius:999px; padding:2px 8px; font-size:11px; font-weight:650; ring:1px; }
+    .title { font-weight:650; }
+    .detail { white-space:pre-wrap; opacity:.9; }
+    .actions { display:flex; flex-wrap:wrap; gap:10px; align-items:center; margin-top:10px; }
+    .btn { background:var(--btn); color:var(--text); border:1px solid var(--border); border-radius:8px; padding:5px 10px; font-size:12px; }
+    .link { font-size:12px; opacity:.8; text-decoration:underline; text-underline-offset:2px; background:none; border:0; color:inherit; cursor:pointer; }
+    .proxy { border-color:rgba(245,158,11,.4); background:rgba(245,158,11,.1); }
+    .proxy .pill { background:rgba(245,158,11,.25); color:#fde68a; }
+    .target { border-color:rgba(14,165,233,.4); background:rgba(14,165,233,.1); }
+    .target .pill { background:rgba(14,165,233,.25); color:#bae6fd; }
+    .auth { border-color:rgba(244,63,94,.4); background:rgba(244,63,94,.1); }
+    .auth .pill { background:rgba(244,63,94,.25); color:#fecdd3; }
+    .unknown { border-color:rgba(113,113,122,.45); background:rgba(113,113,122,.12); }
+    .unknown .pill { background:rgba(113,113,122,.35); color:#e4e4e7; }
+  </style>
+</head>
+<body>
+  <h1>路径 B · ProxyErrorBanner 中文分层芯片</h1>
+  <div class="sub">线框：代理 / 目标 / 鉴权 · unknown 中性灰 · 主按钮 / 次链接</div>
+  <div class="stack">
+    <div class="banner proxy">
+      <div class="row"><span class="pill">代理</span><span class="title">代理层失败</span></div>
+      <div class="detail">Failed to fetch · ECONNREFUSED 127.0.0.1:8787</div>
+      <div class="actions"><button class="btn">检查本地代理</button><button class="btn">切换桌面直连</button><button class="link">查看通道说明</button></div>
+    </div>
+    <div class="banner target">
+      <div class="row"><span class="pill">目标</span><span class="title">目标服务失败</span></div>
+      <div class="detail">HTTP 502 · ENOTFOUND api.internal.example</div>
+      <div class="actions"><button class="btn">检查 BaseURL / VPN</button></div>
+    </div>
+    <div class="banner auth">
+      <div class="row"><span class="pill">鉴权</span><span class="title">鉴权层失败</span></div>
+      <div class="detail">401 Unauthorized · Bearer 无效</div>
+      <div class="actions"><button class="btn">检查 Token / Auth</button></div>
+    </div>
+    <div class="banner unknown">
+      <div class="row"><span class="pill">未知</span><span class="title">请求失败（请按层排查）</span></div>
+      <div class="detail">Unexpected error</div>
+      <div class="actions"><button class="btn">查代理 :8787</button><button class="btn">切换桌面直连</button><button class="link">查环境 / BaseURL</button></div>
+    </div>
+  </div>
+</body>
+</html>

apps/web/public/favicon.svg

@@ -1,15 +1,5 @@
-<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 64 64">
-  <defs>
-    <linearGradient id="g" x1="0" y1="0" x2="64" y2="64" gradientUnits="userSpaceOnUse">
-      <stop offset="0" stop-color="#2563EB"/>
-      <stop offset="1" stop-color="#06B6D4"/>
-    </linearGradient>
-  </defs>
-  <rect width="64" height="64" rx="14" fill="url(#g)"/>
-  <g stroke="#fff" stroke-width="5" stroke-linecap="round" stroke-linejoin="round" fill="none">
-    <path d="M17 25h26"/>
-    <path d="M37 19l6 6-6 6"/>
-    <path d="M47 39H21"/>
-    <path d="M27 33l-6 6 6 6"/>
-  </g>
+<svg xmlns="http://www.w3.org/2000/svg" width="512" height="512" viewBox="0 0 512 512">
+  <rect width="512" height="512" rx="112" fill="#0B182C"/>
+  <path d="M200 130c-48 0-70 28-70 70v28c0 22-14 34-34 38v20c20 4 34 16 34 38v28c0 42 22 70 70 70" fill="none" stroke="#FFFFFF" stroke-width="36" stroke-linecap="round"/>
+  <path d="M312 130c48 0 70 28 70 70v28c0 22 14 34 34 38v20c-20 4-34 16-34 38v28c0 42-22 70-70 70" fill="none" stroke="#3B82F6" stroke-width="36" stroke-linecap="round"/>
 </svg>