feat(benchmark): the built-in benchmark, redesigned into the console

The old standalone benchmark.html (Russian-only, Tailwind+Chart.js from CDNs,
never shipped in the crate) becomes a proper sidebar view. Same scoring ideas,
reimplemented: keyword checks with |-synonyms, think-tag stripping, tail-loop
detection, pass/partial/fail — plus what the old page never had: runs go
through the LIVE pipeline (pinned per model, streamed), so every test also
measures tok/s and time-to-first-token with the gateway's real token counts.

A built-in suite of 12 language-neutral probes (math, logic, code, QA,
instruction-following, extraction, translation, JSON formatting); the ⚡ quick
mode runs the 6 short ones — about a minute on a local model. Results: score
bars per model sorted best-first, a per-test grid (click a cell for the full
answer), previous runs and custom tests kept in the browser.

22 new strings in all 7 languages.

web/js/app.js

@@ -12,6 +12,7 @@ import { renderKeys } from "./views/keys.js";
 import { renderPlayground } from "./views/playground.js";
 import { renderSettings } from "./views/settings.js";
 import { renderLogs } from "./views/logs.js";
+import { renderBenchmark } from "./views/benchmark.js";
 import { renderOnboarding } from "./views/onboarding.js";
 
 const ROUTES = [
@@ -22,6 +23,7 @@ const ROUTES = [
   { id: "protocols", icon: "⇆", view: renderProtocols },
   { id: "keys", icon: "🔑", view: renderKeys },
   { id: "playground", icon: "✦", view: renderPlayground },
+  { id: "benchmark", icon: "⏱", view: renderBenchmark },
   { id: "logs", icon: "📜", view: renderLogs },
   { id: "settings", icon: "⚙", view: renderSettings },
   { id: "onboarding", icon: "✦", view: renderOnboarding, hidden: true },