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/ui/prerequisites.tsx

@@ -0,0 +1,52 @@
+import React from "react"
+import { CheckCircle2, ListChecks } from "lucide-react"
+import { cn } from "@/lib/utils"
+
+interface PrerequisiteItem {
+  label: React.ReactNode
+  check?: string
+}
+
+interface PrerequisitesProps {
+  title?: string
+  items: PrerequisiteItem[]
+  className?: string
+}
+
+export const Prerequisites: React.FC<PrerequisitesProps> = ({
+  title = "Before you start",
+  items,
+  className,
+}) => {
+  return (
+    <div
+      className={cn(
+        "my-6 rounded-lg border border-gray-200 bg-gray-50 p-5",
+        className,
+      )}
+    >
+      <div className="flex items-center gap-2 mb-3">
+        <ListChecks className="h-5 w-5 text-gray-700" aria-hidden="true" />
+        <h4 className="font-semibold text-gray-900 m-0">{title}</h4>
+      </div>
+      <ul className="space-y-2 list-none pl-0">
+        {items.map((item, idx) => (
+          <li key={idx} className="flex items-start gap-2">
+            <CheckCircle2
+              className="h-4 w-4 text-emerald-600 flex-shrink-0 mt-1"
+              aria-hidden="true"
+            />
+            <div className="flex-1 text-sm text-gray-800">
+              <div>{item.label}</div>
+              {item.check && (
+                <code className="mt-1 inline-block text-xs bg-white border border-gray-200 rounded px-1.5 py-0.5 text-gray-700">
+                  {item.check}
+                </code>
+              )}
+            </div>
+          </li>
+        ))}
+      </ul>
+    </div>
+  )
+}