complete i18n migration to /[locale]/ with EN+ES content

Full rewrite of the docs site under app/[locale]/ with next-intl
in localePrefix:"always" mode. Every page now exists at both
/en/<path> and /es/<path>; the root / shows a meta-refresh + JS
redirect to /<defaultLocale>/ so GitHub Pages serves something
on the apex URL.

Highlights:
- 107 doc pages migrated to file-per-page JSON namespaces under
  messages/en/ and messages/es/. Spanish content is fully
  translated (no copy-of-English placeholders).
- New documentation for the Active Suppressions section in the
  Settings tab and the per-event Dismiss dropdown in the Health
  Monitor modal.
- New screenshots: dismiss-duration-dropdown.png and an updated
  health-suppression-settings.png.
- Pagefind integrated for client-side search; index is built on
  every CI deploy (not committed).
- RSS feeds: per-locale at /<locale>/rss.xml plus root /rss.xml
  for backward compat.
- Removed the dead app/[locale]/guides/[slug]/ route — every
  guide now has its own static page and no markdown source
  remains.
- Fixed orphan link /guides/nvidia -> /guides/nvidia-manual in
  docs/hardware/nvidia-host.
- Removed obsolete components (footer2, calendar, drawer).

Verified locally with `npm ci && npm run build`: 2804 files in
out/, 231 pages indexed by pagefind, root redirect intact, both
locale roots and the new Active Suppressions docs render OK.

web/components/CopyButton.tsx

@@ -0,0 +1,39 @@
+"use client"
+
+import { useState } from "react"
+import { Copy, Check } from "lucide-react"
+
+/**
+ * Copy-to-clipboard button used by the (server-rendered) CopyableCode
+ * wrapper. Kept as a tiny client component so the parent can stay on
+ * the server side and run Shiki's syntax-highlighter at build time
+ * (no highlighter JS in the client bundle, just the pre-coloured
+ * HTML).
+ */
+export function CopyButton({ text }: { text: string }) {
+  const [isCopied, setIsCopied] = useState(false)
+
+  const handleCopy = async () => {
+    try {
+      await navigator.clipboard.writeText(text)
+      setIsCopied(true)
+      setTimeout(() => setIsCopied(false), 2000)
+    } catch {
+      // clipboard may be unavailable on insecure origins; swallow.
+    }
+  }
+
+  return (
+    <button
+      onClick={handleCopy}
+      className="absolute top-2 right-2 p-1.5 bg-gray-800 hover:bg-gray-700 border border-gray-700 rounded-md transition-colors"
+      aria-label="Copy code"
+    >
+      {isCopied ? (
+        <Check className="h-4 w-4 text-green-400" />
+      ) : (
+        <Copy className="h-4 w-4 text-gray-300" />
+      )}
+    </button>
+  )
+}