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/lib/navigation.ts

@@ -66,11 +66,11 @@ export const navItems: NavItem[] = [
 ];
 
 /**
- * Mobile bottom bar items (subset of primary nav).
+ * Mobile bottom bar items. Mirrors the FULL desktop sidebar (all primary nav
+ * items) so every page is reachable on mobile; the bar scrolls horizontally on
+ * narrow screens (see MobileNav).
  */
-export const mobileNavItems: NavItem[] = navItems.filter((item) =>
-  ["/dashboard", "/messages", "/voice", "/media"].includes(item.href),
-);
+export const mobileNavItems: NavItem[] = navItems;
 
 export type NavItemId = (typeof navItems)[number]["href"];