feat(inventory): Inventur abbrechen und nach Status filtern (US-6.4)

Ermöglicht das Abbrechen von Inventuren (OPEN/COUNTING → CANCELLED) mit
Pflicht-Begründung sowie das Filtern der Inventurliste nach Status.

frontend/apps/cli/src/components/inventory/InventoryCountDetailScreen.tsx

@@ -1,4 +1,4 @@
-import React, { useEffect, useState } from 'react';
+import { useEffect, useState } from 'react';
 import { Box, Text, useInput } from 'ink';
 import TextInput from 'ink-text-input';
 import { useNavigation } from '../../state/navigation-context.js';
@@ -11,7 +11,7 @@ import { SuccessDisplay } from '../shared/SuccessDisplay.js';
 import { INVENTORY_COUNT_STATUS_LABELS } from '@effigenix/api-client';
 import type { InventoryCountStatus, CountItemDTO } from '@effigenix/api-client';
 
-type Mode = 'view' | 'menu' | 'record-item' | 'record-amount' | 'confirm-start' | 'confirm-complete';
+type Mode = 'view' | 'menu' | 'record-item' | 'record-amount' | 'confirm-start' | 'confirm-complete' | 'cancel-reason' | 'confirm-cancel';
 
 const STATUS_COLORS: Record<InventoryCountStatus, string> = {
   OPEN: 'yellow',
@@ -33,6 +33,7 @@ export function InventoryCountDetailScreen() {
     startInventoryCount,
     recordCountItem,
     completeInventoryCount,
+    cancelInventoryCount,
     clearError,
   } = useInventoryCounts();
   const { articleName, locationName } = useStockNameLookup();
@@ -42,6 +43,7 @@ export function InventoryCountDetailScreen() {
   const [itemIndex, setItemIndex] = useState(0);
   const [amount, setAmount] = useState('');
   const [success, setSuccess] = useState<string | null>(null);
+  const [cancelReason, setCancelReason] = useState('');
 
   const countId = params.inventoryCountId ?? '';
 
@@ -61,12 +63,14 @@ export function InventoryCountDetailScreen() {
     const actions: { label: string; action: string }[] = [];
     if (inventoryCount.status === 'OPEN') {
       actions.push({ label: 'Zählung starten', action: 'start' });
+      actions.push({ label: 'Inventur abbrechen', action: 'cancel' });
     }
     if (inventoryCount.status === 'COUNTING') {
       actions.push({ label: 'Position erfassen', action: 'record' });
       if (allCounted && isDifferentUser) {
         actions.push({ label: 'Inventur abschließen', action: 'complete' });
       }
+      actions.push({ label: 'Inventur abbrechen', action: 'cancel' });
     }
     return actions;
   };
@@ -108,6 +112,16 @@ export function InventoryCountDetailScreen() {
     }
   };
 
+  const handleCancel = async () => {
+    if (!cancelReason.trim()) return;
+    const result = await cancelInventoryCount(countId, cancelReason.trim());
+    if (result) {
+      setSuccess('Inventur abgebrochen.');
+      setCancelReason('');
+      setMode('view');
+    }
+  };
+
   useInput((input, key) => {
     if (loading) return;
 
@@ -116,6 +130,17 @@ export function InventoryCountDetailScreen() {
       return;
     }
 
+    if (mode === 'cancel-reason') {
+      if (key.escape) { setCancelReason(''); setMode('view'); }
+      return;
+    }
+
+    if (mode === 'confirm-cancel') {
+      if (input.toLowerCase() === 'j') void handleCancel();
+      if (input.toLowerCase() === 'n' || key.escape) setMode('view');
+      return;
+    }
+
     if (mode === 'confirm-start') {
       if (input.toLowerCase() === 'j') void handleStart();
       if (input.toLowerCase() === 'n' || key.escape) setMode('view');
@@ -147,6 +172,7 @@ export function InventoryCountDetailScreen() {
         if (action === 'start') setMode('confirm-start');
         else if (action === 'record') { setMode('record-item'); setItemIndex(0); }
         else if (action === 'complete') setMode('confirm-complete');
+        else if (action === 'cancel') { setCancelReason(''); setMode('cancel-reason'); }
       }
       if (key.escape) setMode('view');
       return;
@@ -207,6 +233,9 @@ export function InventoryCountDetailScreen() {
         {inventoryCount.completedBy && (
           <Box><Text color="gray">Abgeschl. von:  </Text><Text>{inventoryCount.completedBy}</Text></Box>
         )}
+        {inventoryCount.cancellationReason && (
+          <Box><Text color="gray">Abbruchgrund:   </Text><Text color="red">{inventoryCount.cancellationReason}</Text></Box>
+        )}
         <Box>
           <Text color="gray">Fortschritt:    </Text>
           <Text color={allCounted ? 'green' : 'yellow'}>{progressBar} {countedCount}/{items.length} ({progressPct}%)</Text>
@@ -311,6 +340,33 @@ export function InventoryCountDetailScreen() {
         </Box>
       )}
 
+      {/* Cancel Reason */}
+      {mode === 'cancel-reason' && (
+        <Box flexDirection="column" borderStyle="round" borderColor="red" paddingX={1}>
+          <Text color="red" bold>Inventur abbrechen</Text>
+          <Text color="gray">Bitte Grund eingeben:</Text>
+          <Box>
+            <Text color="gray"> › </Text>
+            <TextInput
+              value={cancelReason}
+              onChange={setCancelReason}
+              onSubmit={() => { if (cancelReason.trim()) setMode('confirm-cancel'); }}
+              focus={true}
+            />
+          </Box>
+          <Text color="gray" dimColor>Enter bestätigen · Escape abbrechen</Text>
+        </Box>
+      )}
+
+      {/* Confirm Cancel */}
+      {mode === 'confirm-cancel' && (
+        <Box flexDirection="column" borderStyle="round" borderColor="red" paddingX={1}>
+          <Text color="red" bold>Inventur wirklich abbrechen?</Text>
+          <Text>Grund: {cancelReason}</Text>
+          <Text color="gray" dimColor>[J] Ja · [N] Nein</Text>
+        </Box>
+      )}
+
       {/* Four-eyes hint */}
       {inventoryCount.status === 'COUNTING' && allCounted && !isDifferentUser && (
         <Box>

frontend/apps/cli/src/hooks/useInventoryCounts.ts

@@ -94,6 +94,18 @@ export function useInventoryCounts() {
     }
   }, []);
 
+  const cancelInventoryCount = useCallback(async (id: string, reason: string) => {
+    setState((s) => ({ ...s, loading: true, error: null }));
+    try {
+      const inventoryCount = await client.inventoryCounts.cancel(id, { reason });
+      setState((s) => ({ ...s, inventoryCount, loading: false, error: null }));
+      return inventoryCount;
+    } catch (err) {
+      setState((s) => ({ ...s, loading: false, error: errorMessage(err) }));
+      return null;
+    }
+  }, []);
+
   const clearError = useCallback(() => {
     setState((s) => ({ ...s, error: null }));
   }, []);
@@ -106,6 +118,7 @@ export function useInventoryCounts() {
     startInventoryCount,
     recordCountItem,
     completeInventoryCount,
+    cancelInventoryCount,
     clearError,
   };
 }