feat(cortex): no-show casus — intent flow, brief-rescript en document artifact

Cortex handelt een no-show af vanuit één chatcommando: afspraak
annuleren (declarabiliteits-nudge), en de openstaande concept-
huisartsbrief wordt via LLM herschreven en ter review aangeboden
in een document artifact (human-in-the-loop, PATCH dispatch zet
status op verzendklaar).

- API-routes: context, rescript, cancel, dispatch
- NoShowDocumentBlock: review/edit UI met origineel-vergelijk
- Mock-data voor concept huisartsbrief
- PRD, FO, bouwplan en epics in docs/intent/noshow-case/

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

components/cortex/blocks/noshow-document-block.tsx

@@ -0,0 +1,140 @@
+'use client';
+
+import { useState } from 'react';
+import { FileText, ChevronDown, ChevronUp } from 'lucide-react';
+import { Textarea } from '@/components/ui/textarea';
+import { Button } from '@/components/ui/button';
+import { useCortexStore } from '@/stores/cortex-store';
+import { cn } from '@/lib/utils';
+
+interface NoShowDocumentPrefill {
+  documentId: string;
+  content: string;
+  title: string;
+  originalContent?: string;
+  rescriptWarning?: string;
+}
+
+interface NoShowDocumentBlockProps {
+  prefill: NoShowDocumentPrefill;
+}
+
+export function NoShowDocumentBlock({ prefill }: NoShowDocumentBlockProps) {
+  const [content, setContent] = useState<string>(prefill.content ?? '');
+  const [showOriginal, setShowOriginal] = useState(false);
+  const [isSubmitting, setIsSubmitting] = useState(false);
+  const [isDone, setIsDone] = useState(false);
+
+  const addChatMessage = useCortexStore((s) => s.addChatMessage);
+  const setNoShowStep = useCortexStore((s) => s.setNoShowStep);
+
+  const handleDispatch = async () => {
+    setIsSubmitting(true);
+
+    try {
+      const res = await fetch('/api/cortex/noshow/dispatch', {
+        method: 'PATCH',
+        headers: { 'Content-Type': 'application/json' },
+        body: JSON.stringify({
+          documentId: prefill.documentId,
+          finalContent: content,
+        }),
+      });
+
+      if (!res.ok) throw new Error('Dispatch mislukt');
+
+      setIsDone(true);
+      setNoShowStep('done');
+      addChatMessage({
+        type: 'assistant',
+        content: 'Brief is verzendklaar gemaakt. De no-show afhandeling is compleet.',
+      });
+    } catch {
+      addChatMessage({
+        type: 'error',
+        content: 'Opslaan mislukt. Probeer het opnieuw.',
+      });
+    } finally {
+      setIsSubmitting(false);
+    }
+  };
+
+  return (
+    <div className="w-full max-w-2xl">
+      {/* Header */}
+      <div className="flex items-center gap-2 mb-4">
+        <FileText className="w-5 h-5 text-slate-600" />
+        <h2 className="text-lg font-semibold text-slate-800">
+          {prefill.title || 'Huisartsbrief'}
+        </h2>
+        <span className="ml-auto text-xs text-amber-600 bg-amber-50 px-2 py-0.5 rounded font-medium">
+          Aangepast door Cortex
+        </span>
+      </div>
+
+      {/* LLM waarschuwing bij fallback naar origineel */}
+      {prefill.rescriptWarning && (
+        <div className="mb-3 p-3 bg-amber-50 border border-amber-200 rounded text-sm text-amber-800">
+          ⚠️ {prefill.rescriptWarning}
+        </div>
+      )}
+
+      {/* Bewerkbare tekstinhoud */}
+      <Textarea
+        value={content}
+        onChange={(e) => setContent(e.target.value)}
+        disabled={isDone}
+        className={cn(
+          'min-h-[320px] font-mono text-sm resize-y',
+          isDone && 'opacity-60 cursor-not-allowed'
+        )}
+        placeholder="Brief inhoud..."
+      />
+
+      {/* Origineel bekijken — collapsible */}
+      {prefill.originalContent && (
+        <div className="mt-2">
+          <button
+            type="button"
+            onClick={() => setShowOriginal(!showOriginal)}
+            className="flex items-center gap-1 text-xs text-slate-500 hover:text-slate-700 transition-colors"
+          >
+            {showOriginal ? (
+              <ChevronUp className="w-3 h-3" />
+            ) : (
+              <ChevronDown className="w-3 h-3" />
+            )}
+            {showOriginal ? 'Origineel verbergen' : 'Originele brief bekijken'}
+          </button>
+
+          {showOriginal && (
+            <div className="mt-2 p-3 bg-slate-50 border border-slate-200 rounded text-sm text-slate-500 font-mono whitespace-pre-wrap">
+              {prefill.originalContent}
+            </div>
+          )}
+        </div>
+      )}
+
+      {/* Footer */}
+      <div className="mt-4 flex items-center justify-between border-t border-slate-200 pt-4">
+        <span className="text-xs text-slate-400">
+          {isDone ? '✓ Brief is verzendklaar' : 'Controleer en pas aan indien nodig'}
+        </span>
+
+        {isDone ? (
+          <span className="text-sm font-medium text-green-600">
+            ✓ Verzendklaar
+          </span>
+        ) : (
+          <Button
+            onClick={handleDispatch}
+            disabled={isSubmitting || content.trim().length === 0}
+            className="bg-slate-800 hover:bg-slate-700 text-white"
+          >
+            {isSubmitting ? 'Opslaan...' : 'Akkoord & Verzendklaar →'}
+          </Button>
+        )}
+      </div>
+    </div>
+  );
+}