Enhance ExerciseFormPageRoot with save and close functionality

- Added a new `handleSaveAndClose` function to allow users to save and navigate back to the exercise list.
- Updated `performSaveAttempt` to accept a `closeAfter` parameter for conditional navigation.
- Refactored form submission handling to include separate actions for saving and saving with closure.
- Integrated `PageFormEditorChrome` for improved layout and user experience, including a back navigation option.

frontend/src/components/exercises/ExerciseFormPageRoot.jsx

@@ -26,6 +26,7 @@ import { COMBINATION_ARCHETYPE_OPTIONS, ARCHETYPE_DEFAULT_REP_SERIES_COUNT, defa
 import { readSlotProfilesV1, normalizeAdvanceMode, parseComboRepSeriesCountUi } from '../../utils/combinationMethodProfileUi'
 import { GripVertical } from 'lucide-react'
 import UnsavedChangesPrompt from '../UnsavedChangesPrompt'
+import PageFormEditorChrome from '../PageFormEditorChrome'
 import { useBeforeUnloadWhen, useUnsavedChangesBlocker } from '../../hooks/useUnsavedChangesBlocker'
 
 const INTENSITY_OPTIONS = [
@@ -836,7 +837,7 @@ function ExerciseFormPageRoot() {
   }
 
   const performSaveAttempt = useCallback(
-    async ({ fromUnsavedDialog = false } = {}) => {
+    async ({ fromUnsavedDialog = false, closeAfter = false } = {}) => {
       if (!formData.title || formData.title.trim().length < 3) {
         toast.error('Titel mindestens 3 Zeichen')
         return false
@@ -940,12 +941,15 @@ function ExerciseFormPageRoot() {
           setVariants((ex.variants || []).map(apiVariantToRow))
           setFormDirty(false)
           toast.success('Gespeichert.')
+          if (closeAfter) navigate('/exercises')
           return true
         }
         const created = await api.createExercise(payload)
         setFormDirty(false)
         toast.success('Übung angelegt.')
-        if (!fromUnsavedDialog) {
+        if (closeAfter) {
+          navigate('/exercises')
+        } else if (!fromUnsavedDialog) {
           navigate(`/exercises/${created.id}/edit`, { replace: true })
         }
         return true
@@ -959,10 +963,39 @@ function ExerciseFormPageRoot() {
     [exerciseId, formData, isEdit, navigate, toast],
   )
 
-  const handleSubmit = async (e) => {
-    e.preventDefault()
-    await performSaveAttempt({ fromUnsavedDialog: false })
-  }
+  const handleSubmit = useCallback(
+    async (e) => {
+      e?.preventDefault?.()
+      await performSaveAttempt({ fromUnsavedDialog: false, closeAfter: false })
+    },
+    [performSaveAttempt],
+  )
+
+  const handleSaveAndClose = useCallback(
+    async (e) => {
+      e?.preventDefault?.()
+      await performSaveAttempt({ fromUnsavedDialog: false, closeAfter: true })
+    },
+    [performSaveAttempt],
+  )
+
+  const goBackToList = useCallback(() => {
+    navigate('/exercises')
+  }, [navigate])
+
+  const actionConfig = useMemo(
+    () => ({
+      formId: 'exercise-form',
+      saving,
+      isNew: !isEdit,
+      onSave: handleSubmit,
+      onSaveAndClose: handleSaveAndClose,
+      onCancel: goBackToList,
+      showSave: true,
+      showSaveAndClose: true,
+    }),
+    [saving, isEdit, handleSubmit, handleSaveAndClose, goBackToList],
+  )
 
   const handleUnsavedDialogSave = async () => {
     const ok = await performSaveAttempt({ fromUnsavedDialog: true })
@@ -1162,27 +1195,28 @@ function ExerciseFormPageRoot() {
   }
 
   return (
-    <div style={{ padding: '12px' }} className="app-page">
-      <div style={{ marginBottom: '12px' }}>
-        <button type="button" className="btn btn-secondary" onClick={() => navigate('/exercises')}>
-          ← Übersicht
-        </button>
-        {isEdit && (
-          <button
-            type="button"
+    <PageFormEditorChrome
+      testId="exercise-form-page"
+      title={isEdit ? 'Übung bearbeiten' : 'Neue Übung'}
+      backTo="/exercises"
+      backLabel="Übersicht"
+      actionConfig={actionConfig}
+    >
+      {isEdit ? (
+        <p style={{ margin: '0 0 12px' }}>
+          <Link
+            to={`/exercises/${exerciseId}`}
+            state={{ fromExerciseEdit: true }}
             className="btn btn-secondary"
-            style={{ marginLeft: '8px' }}
-            onClick={() => navigate(`/exercises/${exerciseId}`, { state: { fromExerciseEdit: true } })}
+            style={{ fontSize: '0.875rem' }}
           >
             Ansehen
-          </button>
-        )}
-      </div>
+          </Link>
+        </p>
+      ) : null}
 
       <div className="card">
-        <h1 style={{ marginTop: 0, fontSize: '1.25rem' }}>{isEdit ? 'Übung bearbeiten' : 'Neue Übung'}</h1>
-
-        <form onSubmit={handleSubmit}>
+        <form id="exercise-form" onSubmit={handleSubmit}>
           <div className="form-row">
             <label className="form-label">Titel *</label>
             <input
@@ -1943,12 +1977,6 @@ function ExerciseFormPageRoot() {
               </p>
             </div>
           ) : null}
-
-          <div style={{ marginTop: '16px' }}>
-            <button type="submit" className="btn btn-primary" disabled={saving}>
-              {saving ? 'Speichern…' : isEdit ? 'Speichern' : 'Anlegen & weiter'}
-            </button>
-          </div>
         </form>
       </div>
 
@@ -2439,8 +2467,9 @@ function ExerciseFormPageRoot() {
         isBusy={saving}
         onSave={handleUnsavedDialogSave}
         onDiscardWithoutSave={() => setFormDirty(false)}
+        detail="Du hast ungespeicherte Änderungen vorgenommen. Möchtest du die Seite wirklich verlassen?"
       />
-    </div>
+    </PageFormEditorChrome>
   )
 }