fix(logs): Ereignis-Bearbeitung sichern und Warnung bei ungespeicherten Änderungen

Normalisiert partielle Logbuch-Events beim Speichern (z. B. Besegelung) und warnt beim Verlassen von Editor, Tabs und Browser.

Co-authored-by: Cursor <cursoragent@cursor.com>

client/src/context/UnsavedChangesContext.tsx

@@ -0,0 +1,77 @@
+import {
+  createContext,
+  useContext,
+  useCallback,
+  useEffect,
+  useRef,
+  useMemo,
+  type ReactNode
+} from 'react'
+import { useTranslation } from 'react-i18next'
+import { useDialog } from '../components/ModalDialog.tsx'
+
+interface UnsavedChangesContextValue {
+  setDirty: (source: string, dirty: boolean) => void
+  confirmLeave: () => Promise<boolean>
+}
+
+const UnsavedChangesContext = createContext<UnsavedChangesContextValue | null>(null)
+
+export function UnsavedChangesProvider({ children }: { children: ReactNode }) {
+  const { t } = useTranslation()
+  const { showConfirm } = useDialog()
+  const dirtySources = useRef(new Set<string>())
+
+  const setDirty = useCallback((source: string, dirty: boolean) => {
+    if (dirty) dirtySources.current.add(source)
+    else dirtySources.current.delete(source)
+  }, [])
+
+  const confirmLeave = useCallback(async (): Promise<boolean> => {
+    if (dirtySources.current.size === 0) return true
+    return showConfirm(
+      t('common.unsaved_changes_message'),
+      t('common.unsaved_changes_title'),
+      t('common.unsaved_changes_leave'),
+      t('common.unsaved_changes_stay')
+    )
+  }, [showConfirm, t])
+
+  useEffect(() => {
+    const handler = (e: BeforeUnloadEvent) => {
+      if (dirtySources.current.size === 0) return
+      e.preventDefault()
+      e.returnValue = ''
+    }
+    window.addEventListener('beforeunload', handler)
+    return () => window.removeEventListener('beforeunload', handler)
+  }, [])
+
+  const value = useMemo(() => ({ setDirty, confirmLeave }), [setDirty, confirmLeave])
+
+  return (
+    <UnsavedChangesContext.Provider value={value}>
+      {children}
+    </UnsavedChangesContext.Provider>
+  )
+}
+
+export function useUnsavedChangesContext(): UnsavedChangesContextValue {
+  const ctx = useContext(UnsavedChangesContext)
+  if (!ctx) {
+    throw new Error('useUnsavedChangesContext must be used within UnsavedChangesProvider')
+  }
+  return ctx
+}
+
+/** Register a form/view as having unsaved changes (cleared automatically on unmount). */
+export function useRegisterUnsavedChanges(source: string, isDirty: boolean) {
+  const { setDirty, confirmLeave } = useUnsavedChangesContext()
+
+  useEffect(() => {
+    setDirty(source, isDirty)
+    return () => setDirty(source, false)
+  }, [source, isDirty, setDirty])
+
+  return { confirmLeave }
+}