fix(frontend): mobile navbar navigation + SSR hydration mismatch

Root cause of 'navbar mobile tak bisa pindah halaman': Next <Link>
client-side navigation is dead app-wide. A React hydration mismatch
(#418: 'server rendered text didn't match the client') is thrown by the
SSR-seeded live feeds — relative times (formatRelativeTime(e.edited_at) /
m.created_at) computed with Date.now() render slightly differently on
server vs client, which breaks the Next client router (router.push is a
no-op). The desktop NavRail worked only because it uses plain <a href>
(hard navigation bypasses the broken router).

Fixes:
- mobile-nav.tsx: use plain <a href> (NOT Next <Link>), identical to the
  working sidebar NavRail, so mobile nav always navigates regardless of
  router state ('ikuti cara kerja sidebar').
- Add suppressHydrationWarning to the SSR-seeded relative-time spans so
  server/client drift no longer throws #418 (EditHistory, LiveModerationFeed,
  messages/results + detail rows, recordings, TermGlossary,
  ChannelCultureGlossary, CategoryDrilldown).

Verified on non-prod :4024 @375px: Voice/Media/Search all navigate, no #418
in console. Plan: .hermes/plans/mobile-nav-hydration-fix.md

services/frontend/src/components/LiveModerationFeed.tsx

@@ -135,7 +135,10 @@ export function LiveModerationFeed({
                         [{a.categories.slice(0, 2).join(", ")}]
                       </span>
                     ) : null}
-                    <span className="ml-auto font-mono text-[10px] text-ink-faint">
+                    <span
+                      className="ml-auto font-mono text-[10px] text-ink-faint"
+                      suppressHydrationWarning
+                    >
                       {formatRelativeTime(a.created_at)}
                     </span>
                   </div>