feat(benchmark): smart-routing mode is the point — live results, per-model cost

The benchmark now leads with the product's actual feature. Two explicit modes:

  🧭 Smart routing (default) — every probe goes through cortiq-auto; each row
     shows the router's task label judged against the expected one (✓/✗ with
     "expected: …"), the complexity tier, the chosen model with what that
     request cost, and a task-rule badge when a routing rule fired. KPIs:
     answer quality, classification accuracy, TTFT, tok/s and money spent,
     plus a "requests went to" distribution with per-model cost.
  🎯 Individual models — the old head-to-head comparison, now as the clearly
     separate option (model checkboxes appear only here).

The suite covers all 8 taxonomy labels (added summarization, creative-writing
and chitchat probes; expected labels annotated per test). Results are LIVE:
the table grows a row after every test (with a small fade-in), the progress
card shows the prompt being asked, and a 🏁 verdict toast lands at the end
with the score and the total spend.

12 new strings in all 7 languages.

web/js/i18n/zh.js

@@ -587,4 +587,18 @@ export default {
   "bm.addTest": "添加测试",
   "bm.emptyAnswer": "回答为空",
   "bm.loopDetected": "检测到循环",
+
+  // benchmark: routing mode, cost, live
+  "bm.mode.routing": "智能路由",
+  "bm.mode.models": "单独模型",
+  "bm.mode.routingDesc": "测试产品核心能力：每个探测都经过 cortiq-auto — 可以看到路由器识别的任务、选中的模型、是否符合预期，以及花费了多少。",
+  "bm.mode.modelsDesc": "同一套测试固定在所选模型上 — 绕过路由器，直接对比它们的质量、速度与成本。",
+  "bm.answersOk": "回答正确",
+  "bm.classAcc": "任务分类",
+  "bm.modelDist": "请求流向",
+  "bm.expectedLbl": "预期：",
+  "bm.answer": "回答",
+  "bm.liveRunning": "进行中……",
+  "bm.spent": "花费",
+  "bm.verdict": "🏁 完成：回答 {p}，花费 {s}",
 };