feat(ui): mobile responsiveness audit + type fixes

Mobile Responsiveness:
- Viewport meta tags toegevoegd in layout.tsx
- EPD header: patient details verborgen op mobiel, zoekbalk responsive
- Agenda: auto-switch naar dagview op mobiel, mini-kalender verborgen
- Agenda toolbar: verticale stacking, Week/Werkweek knoppen verborgen
- Patiëntenlijst: compact icoon-only button op mobiel
- Verpleegrapportage: verticale flow i.p.v. twee-koloms layout
- Cortex: artifact overlay met slide-in animatie op mobiel
- Cortex: "Terug" knop toegevoegd aan artifact panels
- Toast feedback bij succesvolle afspraak creatie

Code Quality Fixes (KISS/DRY):
- Resize listener vervangen door bestaande useMediaQuery hook
- Dubbele flex class opgeschoond in epd-header.tsx
- userScalable: false verwijderd (accessibility)

Type Fixes:
- actions.ts: status literal type met 'as const'
- agenda-block.tsx: dateRange start/end optioneel
- chat-empty-state.tsx: framer-motion ease type
- cortex-store.ts: ChatEntities.dateRange consistent met Zod schema

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

app/epd/agenda/components/agenda-view.tsx

@@ -10,6 +10,7 @@ import React, { useState, useCallback, useRef, useTransition, useEffect } from '
 import dynamic from 'next/dynamic';
 import { startOfWeek, endOfWeek, addDays, format } from 'date-fns';
 import { toast } from '@/hooks/use-toast';
+import { useMediaQuery } from '@/hooks/use-media-query';
 
 // Lazy load FullCalendar component (~150KB+ savings)
 const AgendaCalendar = dynamic(
@@ -62,6 +63,14 @@ export function AgendaView({ initialEvents, initialDate, highlightEncounterId }:
   const [pendingReschedule, setPendingReschedule] = useState<PendingReschedule | null>(null);
   const [isRescheduling, setIsRescheduling] = useState(false);
 
+  // Auto-switch to day view on mobile
+  const isMobile = useMediaQuery('(max-width: 767px)');
+  useEffect(() => {
+    if (isMobile) {
+      setCurrentView('timeGridDay');
+    }
+  }, [isMobile]);
+
   const calendarRef = useRef<{ getApi: () => { prev: () => void; next: () => void; today: () => void; changeView: (view: string) => void; getDate: () => Date } } | null>(null);
 
   // Auto-open appointment modal when navigating from a report
@@ -118,7 +127,7 @@ export function AgendaView({ initialEvents, initialDate, highlightEncounterId }:
 
   // Handle date range change from calendar
   const handleDateChange = useCallback((start: Date, end: Date) => {
-    setCurrentDate((prev) => 
+    setCurrentDate((prev) =>
       prev.toDateString() === start.toDateString() ? prev : start
     );
     fetchEvents(start, end);
@@ -246,7 +255,7 @@ export function AgendaView({ initialEvents, initialDate, highlightEncounterId }:
 
       <div className="flex flex-1 gap-4 min-h-0">
         {/* Mini calendar sidebar */}
-        <div className="w-64 flex-shrink-0">
+        <div className="w-64 flex-shrink-0 hidden md:block">
           <MiniCalendar
             selectedDate={currentDate}
             onDateSelect={handleMiniCalendarDateSelect}