fix(frontend): mobile navbar reachable to all pages + responsive form controls

- Root cause of 'navbar mobile tak bisa pindah halaman': the chatbot FAB
  (fixed right-4 bottom-5 z-50) overlapped the rightmost mobile bottom-nav
  items (z-40) and intercepted taps. Raise the FAB above the nav on mobile
  (bottom above nav, md:bottom-5 on desktop) so it never blocks nav taps.
- Mobile bottom nav now mirrors the FULL desktop sidebar (all 7 items:
  dashboard, messages, voice, media, recordings, moderation, analysis);
  horizontally scrollable + snap-to-active on narrow screens.
- Select dropdown: clamp portal position within viewport + min-width so it
  never overflows off-screen on mobile triggers near the right edge; larger
  tap targets on touch.
- Input/Textarea: text-base (16px) on touch to prevent iOS auto-zoom on
  focus, text-sm on >=sm; comfortable mobile min-height for chat input.
- Add .hermes/plans/mobile-nav-form-responsive.md spec.

services/frontend/src/app/(dashboard)/messages/view.tsx

@@ -738,11 +738,7 @@ function MessageRow({
           : "border-hairline bg-surface-2 hover:border-hairline-focus hover:bg-surface"
       }`}
     >
-      <Avatar
-        src={m.avatar_url}
-        name={m.server_nick ?? m.username}
-        size={32}
-      />
+      <Avatar src={m.avatar_url} name={m.server_nick ?? m.username} size={32} />
       <div className="min-w-0 flex-1">
         <div className="flex items-center gap-2">
           <span className="truncate text-xs font-semibold text-ink">