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/app/[locale]/docs/network/diagnostics/page.tsx

@@ -0,0 +1,148 @@
+import type { Metadata } from "next"
+import { getTranslations, getMessages, setRequestLocale } from "next-intl/server"
+import { Link } from "@/i18n/navigation"
+import { DocHeader } from "@/components/ui/doc-header"
+import { Callout } from "@/components/ui/callout"
+
+export async function generateMetadata({
+  params,
+}: {
+  params: Promise<{ locale: string }>
+}): Promise<Metadata> {
+  const { locale } = await params
+  const t = await getTranslations({ locale, namespace: "docs.network.diagnostics.meta" })
+  return {
+    title: t("title"),
+    description: t("description"),
+    openGraph: {
+      title: t("ogTitle"),
+      description: t("ogDescription"),
+      type: "article",
+      url: "https://macrimi.github.io/ProxMenux/docs/network/diagnostics",
+    },
+  }
+}
+
+type ConnRow = { test: string; target: string; confirms: string }
+type RelatedItem = { label: string; href: string; tail: string }
+
+export default async function NetworkDiagnosticsPage({
+  params,
+}: {
+  params: Promise<{ locale: string }>
+}) {
+  const { locale } = await params
+  setRequestLocale(locale)
+  const t = await getTranslations({ locale, namespace: "docs.network.diagnostics" })
+
+  const messages = (await getMessages({ locale })) as unknown as {
+    docs: { network: { diagnostics: {
+      connectivity: { rows: ConnRow[] }
+      advanced: { items: string[] }
+      related: { items: RelatedItem[] }
+    } } }
+  }
+  const connRows = messages.docs.network.diagnostics.connectivity.rows
+  const advancedItems = messages.docs.network.diagnostics.advanced.items
+  const relatedItems = messages.docs.network.diagnostics.related.items
+
+  const code = (chunks: React.ReactNode) => <code>{chunks}</code>
+  const strong = (chunks: React.ReactNode) => <strong>{chunks}</strong>
+  const em = (chunks: React.ReactNode) => <em>{chunks}</em>
+  const monitoringLink = (chunks: React.ReactNode) => (
+    <Link href="/docs/network/monitoring" className="text-blue-700 hover:underline">{chunks}</Link>
+  )
+  const backupLink = (chunks: React.ReactNode) => (
+    <Link href="/docs/network/backup-restore" className="text-blue-700 hover:underline">{chunks}</Link>
+  )
+
+  return (
+    <div>
+      <DocHeader
+        title={t("header.title")}
+        description={t("header.description")}
+        section={t("header.section")}
+        estimatedMinutes={3}
+        scriptPath="menus/network_menu.sh"
+      />
+
+      <Callout variant="success" title={t("intro.title")}>
+        {t.rich("intro.body", { strong, monitoringLink, backupLink })}
+      </Callout>
+
+      <h2 className="text-2xl font-semibold mt-10 mb-4 text-gray-900">{t("routing.heading")}</h2>
+      <p className="mb-4 text-gray-800 leading-relaxed">
+        {t.rich("routing.body", { code })}
+      </p>
+      <pre className="rounded-md bg-gray-100 p-4 overflow-x-auto text-xs font-mono text-gray-800 leading-relaxed border border-gray-200">{`Total routes: 4
+
+➡  default via 192.168.1.1 dev vmbr0 onlink
+   • 10.10.10.0/24 dev vmbr1 proto kernel scope link src 10.10.10.1
+   • 169.254.0.0/16 dev vmbr0 scope link metric 1000
+   • 192.168.1.0/24 dev vmbr0 proto kernel scope link src 192.168.1.10
+
+🌍 Default Gateway: 192.168.1.1`}</pre>
+
+      <h2 className="text-2xl font-semibold mt-10 mb-4 text-gray-900">{t("connectivity.heading")}</h2>
+      <p className="mb-4 text-gray-800 leading-relaxed">
+        {t.rich("connectivity.intro", { code })}
+      </p>
+      <div className="overflow-x-auto mb-6">
+        <table className="w-full text-sm border border-gray-200 rounded-md">
+          <thead className="bg-gray-50 text-gray-900">
+            <tr>
+              <th className="text-left px-3 py-2 border-b border-gray-200">{t("connectivity.headerTest")}</th>
+              <th className="text-left px-3 py-2 border-b border-gray-200">{t("connectivity.headerTarget")}</th>
+              <th className="text-left px-3 py-2 border-b border-gray-200">{t("connectivity.headerConfirms")}</th>
+            </tr>
+          </thead>
+          <tbody className="text-gray-800">
+            {connRows.map((row, idx) => (
+              <tr key={row.test} className={idx < connRows.length - 1 ? "border-b border-gray-100" : ""}>
+                <td className="px-3 py-2 align-top whitespace-nowrap"><strong>{row.test}</strong></td>
+                <td className="px-3 py-2 align-top whitespace-nowrap font-mono">{row.target}</td>
+                <td className="px-3 py-2 align-top">{row.confirms}</td>
+              </tr>
+            ))}
+          </tbody>
+        </table>
+      </div>
+      <Callout variant="info" title={t("connectivity.readingTitle")}>
+        {t.rich("connectivity.readingBody", { code })}
+      </Callout>
+
+      <h2 className="text-2xl font-semibold mt-10 mb-4 text-gray-900">{t("advanced.heading")}</h2>
+      <p className="mb-4 text-gray-800 leading-relaxed">{t("advanced.intro")}</p>
+      <ul className="list-disc pl-6 mb-4 text-gray-800 leading-relaxed space-y-2">
+        {advancedItems.map((_, idx) => (
+          <li key={idx}>{t.rich(`advanced.items.${idx}`, { strong, code, em })}</li>
+        ))}
+      </ul>
+      <Callout variant="warning" title={t("advanced.nmTitle")}>
+        {t.rich("advanced.nmBody", { code })}
+      </Callout>
+
+      <h2 className="text-2xl font-semibold mt-10 mb-4 text-gray-900">{t("troubleshoot.heading")}</h2>
+
+      <Callout variant="troubleshoot" title={t("troubleshoot.gwTitle")}>
+        {t.rich("troubleshoot.gwBody", { code })}
+      </Callout>
+
+      <Callout variant="troubleshoot" title={t("troubleshoot.dupTitle")}>
+        {t.rich("troubleshoot.dupBody", { code })}
+      </Callout>
+
+      <h2 className="text-2xl font-semibold mt-10 mb-4 text-gray-900">{t("related.heading")}</h2>
+      <ul className="list-disc pl-6 text-gray-800 leading-relaxed space-y-1">
+        {relatedItems.map((item) => (
+          <li key={item.href}>
+            <Link href={item.href} className="text-blue-600 hover:underline">
+              {item.label}
+            </Link>
+            {item.tail}
+          </li>
+        ))}
+      </ul>
+    </div>
+  )
+}