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/i18n/request.ts

@@ -0,0 +1,63 @@
+import { hasLocale } from "next-intl"
+import { getRequestConfig } from "next-intl/server"
+import { routing } from "./routing"
+import { loadMessages } from "./loadMessages"
+
+/**
+ * Per-request i18n config consumed by next-intl on every page render.
+ *
+ * Loads the entire translation tree for the active locale by walking
+ * `messages/<locale>/` (see loadMessages.ts). Conventions:
+ *
+ *   - `common.json` / `index.json`         → keys merged at root
+ *   - `<name>.json`                        → namespace `<name>.*`
+ *   - sub-directories                      → nested namespace
+ *
+ * Missing translations transparently fall back to English. When a
+ * translator hasn't finished a section yet the user sees the English
+ * text instead of a broken `MISSING_MESSAGE` placeholder.
+ */
+export default getRequestConfig(async ({ requestLocale }) => {
+  const requested = await requestLocale
+  const locale = hasLocale(routing.locales, requested)
+    ? requested
+    : routing.defaultLocale
+
+  const enMessages = loadMessages("en")
+  const localeMessages = locale === "en" ? {} : loadMessages(locale)
+
+  return {
+    locale,
+    messages: deepMerge(enMessages, localeMessages),
+  }
+})
+
+/**
+ * Deep-merge two message trees so the locale's translations override
+ * the English defaults while still falling back to English for any
+ * key the translator hasn't filled in yet.
+ */
+function deepMerge(
+  base: Record<string, unknown>,
+  override: Record<string, unknown>,
+): Record<string, unknown> {
+  const out: Record<string, unknown> = { ...base }
+  for (const [k, v] of Object.entries(override)) {
+    if (
+      v &&
+      typeof v === "object" &&
+      !Array.isArray(v) &&
+      typeof out[k] === "object" &&
+      out[k] !== null &&
+      !Array.isArray(out[k])
+    ) {
+      out[k] = deepMerge(
+        out[k] as Record<string, unknown>,
+        v as Record<string, unknown>,
+      )
+    } else {
+      out[k] = v
+    }
+  }
+  return out
+}