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/data-flow-diagram.tsx

@@ -0,0 +1,99 @@
+import React, { Fragment } from "react"
+import { ArrowRight, ArrowDown, ArrowLeftRight, ArrowUpDown } from "lucide-react"
+import { cn } from "@/lib/utils"
+
+type NodeVariant = "source" | "bridge" | "target"
+
+export interface DataFlowNode {
+  label: string
+  detail?: string
+  variant?: NodeVariant
+}
+
+export interface DataFlowDiagramProps {
+  nodes: DataFlowNode[]
+  arrowLabel?: string
+  bidirectional?: boolean
+  command?: string
+  caption?: string
+  className?: string
+}
+
+const variantStyles: Record<NodeVariant, string> = {
+  source: "border-blue-300 bg-blue-50",
+  bridge: "border-gray-300 bg-gray-50",
+  target: "border-amber-300 bg-amber-50",
+}
+
+const variantLabel: Record<NodeVariant, string> = {
+  source: "text-blue-800",
+  bridge: "text-gray-700",
+  target: "text-amber-800",
+}
+
+export const DataFlowDiagram: React.FC<DataFlowDiagramProps> = ({
+  nodes,
+  arrowLabel,
+  bidirectional = false,
+  command,
+  caption,
+  className,
+}) => {
+  const HorizArrow = bidirectional ? ArrowLeftRight : ArrowRight
+  const VertArrow = bidirectional ? ArrowUpDown : ArrowDown
+  return (
+    <div className={cn("my-6 not-prose", className)}>
+      <div className="flex flex-col md:flex-row md:items-stretch gap-3">
+        {nodes.map((node, i) => {
+          const variant = node.variant ?? "bridge"
+          return (
+            <Fragment key={i}>
+              <div
+                className={cn(
+                  "flex-1 min-w-0 rounded-lg border-2 p-4 flex flex-col",
+                  variantStyles[variant],
+                )}
+              >
+                <div
+                  className={cn(
+                    "text-xs font-semibold uppercase tracking-wide mb-2",
+                    variantLabel[variant],
+                  )}
+                >
+                  {node.label}
+                </div>
+                {node.detail && (
+                  <div className="font-mono text-sm text-gray-800 whitespace-pre-line leading-relaxed">
+                    {node.detail}
+                  </div>
+                )}
+              </div>
+
+              {i < nodes.length - 1 && (
+                <div className="flex md:flex-col items-center justify-center text-gray-500 px-2">
+                  <HorizArrow className="hidden md:block h-5 w-5" aria-hidden />
+                  <VertArrow className="md:hidden h-5 w-5" aria-hidden />
+                  {arrowLabel && (
+                    <span className="ml-2 md:ml-0 md:mt-1 text-xs font-semibold tracking-wide">
+                      {arrowLabel}
+                    </span>
+                  )}
+                </div>
+              )}
+            </Fragment>
+          )
+        })}
+      </div>
+
+      {command && (
+        <pre className="mt-4 rounded-md bg-gray-100 p-3 overflow-x-auto text-xs font-mono text-gray-800 leading-relaxed border border-gray-200">
+          {command}
+        </pre>
+      )}
+
+      {caption && (
+        <p className="mt-2 text-xs text-gray-500 text-center">{caption}</p>
+      )}
+    </div>
+  )
+}