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/components/chatbot/chatbot.tsx

@@ -122,7 +122,7 @@ export function Chatbot() {
           type="button"
           aria-label="Open neural HUD assistant"
           onClick={() => setOpen(true)}
-          className="fixed right-4 bottom-5 z-50 flex size-11 items-center justify-center rounded-full border border-signal/40 bg-surface text-signal shadow-[0_0_20px_var(--color-signal-glow)] transition-all duration-200 hover:scale-105 hover:border-signal hover:bg-signal hover:text-white"
+          className="fixed right-4 z-50 flex size-11 items-center justify-center rounded-full border border-signal/40 bg-surface text-signal shadow-[0_0_20px_var(--color-signal-glow)] transition-all duration-200 hover:scale-105 hover:border-signal hover:bg-signal hover:text-white bottom-[calc(4.75rem+env(safe-area-inset-bottom))] md:bottom-5"
         >
           <Sparkles className="size-5 animate-breathe" />
         </button>
@@ -234,7 +234,7 @@ export function Chatbot() {
               placeholder="Transmit instruction to core..."
               value={input}
               onChange={(e) => setInput(e.target.value)}
-              className="flex-1 rounded-[6px] border border-hairline bg-surface-2 px-3 py-1.5 font-mono text-xs text-ink placeholder:text-ink-faint focus:border-signal focus:outline-none"
+              className="min-h-[38px] flex-1 rounded-[6px] border border-hairline bg-surface-2 px-3 py-1.5 font-mono text-xs text-ink placeholder:text-ink-faint focus:border-signal focus:outline-none"
             />
             <Button
               variant="primary"