feat(exercises): bump version to 0.8.64 and enhance media handling

- Incremented application version to 0.8.64 and updated changelog with new features.
- Improved media handling in the Rich Text Editor with auto-scrolling during drag-and-drop.
- Added new CSS styles for video thumbnails and enhanced layout for media items.
- Removed deprecated `ExerciseAttachmentMediaStrip` from the ExerciseFullContent component.
- Updated ExerciseFormPage to manage form dirty state and prevent data loss on navigation.

backend/version.py

@@ -1,6 +1,6 @@
 # Shinkan Jinkendo Version Information
 
-APP_VERSION = "0.8.63"
+APP_VERSION = "0.8.64"
 BUILD_DATE = "2026-05-08"
 DB_SCHEMA_VERSION = "20260508049"
 
@@ -29,6 +29,13 @@ MODULE_VERSIONS = {
 }
 
 CHANGELOG = [
+    {
+        "version": "0.8.64",
+        "date": "2026-05-08",
+        "changes": [
+            "Übung bearbeiten: Auto-Scroll beim Drag von Medien zu Textfeldern; Medien-Kacheln mehrspaltig; Sektion/Ablauf-Zuordnung an Medien entfernt (nur noch Titel bearbeiten); Picker: Video-Vorschau-Frame; Katalogvorschau ohne Anhangs-Medienliste; Ansehen mit Speichern-Hinweis + Zurück zur Bearbeitung von der Ansicht",
+        ],
+    },
     {
         "version": "0.8.63",
         "date": "2026-05-08",

frontend/src/app.css

@@ -4018,6 +4018,13 @@ a.analysis-split__nav-item {
   height: 100%;
   object-fit: cover;
 }
+.rte-inline-asset-tile__thumb-video {
+  width: 100%;
+  height: 100%;
+  object-fit: cover;
+  display: block;
+  pointer-events: none;
+}
 .rte-inline-asset-tile__thumb-fallback {
   font-size: 11px;
   color: var(--text3);
@@ -4066,9 +4073,10 @@ a.analysis-split__nav-item {
   list-style: none;
   padding: 0;
   margin: 14px 0 0;
-  display: flex;
-  flex-direction: column;
-  gap: 10px;
+  display: grid;
+  grid-template-columns: repeat(auto-fill, minmax(300px, 1fr));
+  gap: 12px;
+  align-items: stretch;
 }
 .exercise-edit-media-strip__item {
   display: flex;
@@ -4129,15 +4137,10 @@ a.analysis-split__nav-item {
 }
 .exercise-edit-media-strip__toolbar {
   display: grid;
-  grid-template-columns: 1fr minmax(120px, 160px);
+  grid-template-columns: 1fr;
   gap: 8px;
   margin-top: 8px;
 }
-@media (max-width: 520px) {
-  .exercise-edit-media-strip__toolbar {
-    grid-template-columns: 1fr;
-  }
-}
 .exercise-edit-media-strip__actions {
   display: flex;
   flex-wrap: wrap;

frontend/src/components/ExerciseFullContent.jsx

@@ -4,7 +4,6 @@
 import React from 'react'
 import { Link } from 'react-router-dom'
 import ExerciseRichTextBlock from './ExerciseRichTextBlock'
-import ExerciseAttachmentMediaStrip from './ExerciseAttachmentMediaStrip'
 
 function TagRow({ exercise }) {
   const tags = []
@@ -118,7 +117,6 @@ export default function ExerciseFullContent({ exercise, loading, error, exercise
           <ExerciseRichTextBlock html={exercise.execution} exerciseId={resolvedId} media={exercise.media} />
         </section>
       )}
-      <ExerciseAttachmentMediaStrip exercise={exercise} exerciseId={resolvedId} />
       {exercise.trainer_notes && (
         <section className="card" style={{ marginTop: '10px', padding: '12px 14px' }}>
           <h3 style={{ fontSize: '0.78rem', textTransform: 'uppercase', color: 'var(--text3)', marginBottom: '8px' }}>

frontend/src/components/ExerciseInlineFileMediaModal.jsx

@@ -11,6 +11,41 @@ import {
 } from '../constants/inlineExerciseMedia'
 import { sanitizeInlineMediaCaption } from '../utils/inlineMediaCaption'
 
+function RtePickerAssetThumb({ asset }) {
+  const id = asset.id
+  const src = resolveMediaAssetFileUrl(id)
+  const mt = (asset.mime_type || '').toLowerCase()
+  if (mt.startsWith('image/') && src) {
+    return <img alt="" src={src} className="rte-inline-asset-tile__thumb-img" />
+  }
+  if (mt.startsWith('video/') && src) {
+    return (
+      <video
+        key={`v-${id}`}
+        className="rte-inline-asset-tile__thumb-video"
+        src={src}
+        muted
+        playsInline
+        preload="metadata"
+        onLoadedMetadata={(e) => {
+          try {
+            const el = e.currentTarget
+            const d = el.duration
+            el.currentTime = Number.isFinite(d) && d > 0 ? Math.min(0.05, d * 0.01) : 0.05
+          } catch (_) {
+            /* ignore */
+          }
+        }}
+      />
+    )
+  }
+  const nameLow = String(asset.original_filename || '').toLowerCase()
+  if (mt.includes('pdf') || nameLow.endsWith('.pdf')) {
+    return <span className="rte-inline-asset-tile__thumb-fallback">PDF</span>
+  }
+  return <span className="rte-inline-asset-tile__thumb-fallback">Datei</span>
+}
+
 /** MIME/Dateiname → Übungs-media_type */
 function inferExerciseMediaType(file) {
   if (!file) return 'image'
@@ -263,9 +298,6 @@ export default function ExerciseInlineFileMediaModal({
                   const selected = selectedAssetId === id
                   const label = it.original_filename || it.copyright_notice || `Archiv #${id}`
                   const linked = assetToExerciseMedia.has(Number(id))
-                  const src = resolveMediaAssetFileUrl(id)
-                  const isImg = (it.mime_type || '').startsWith('image/')
-                  const isVid = (it.mime_type || '').startsWith('video/')
                   return (
                     <button
                       key={id}
@@ -275,13 +307,7 @@ export default function ExerciseInlineFileMediaModal({
                       disabled={busy}
                     >
                       <div className="rte-inline-asset-tile__thumb" aria-hidden>
-                        {isImg && src ? (
-                          <img alt="" src={src} className="rte-inline-asset-tile__thumb-img" />
-                        ) : isVid ? (
-                          <span className="rte-inline-asset-tile__thumb-fallback">▶ Video</span>
-                        ) : (
-                          <span className="rte-inline-asset-tile__thumb-fallback">PDF / Datei</span>
-                        )}
+                        <RtePickerAssetThumb asset={it} />
                       </div>
                       {linked ? (
                         <span className="rte-inline-asset-tile__badge">Bereits verknüpft</span>

frontend/src/components/RichTextEditor.jsx

@@ -6,6 +6,7 @@ import {
   SHINKAN_EXERCISE_MEDIA_DRAG_MIME,
   parseExerciseMediaDragPayload,
 } from '../utils/exerciseInlineMediaRefs'
+import { autoScrollForDragNearEdges } from '../utils/dragAutoScroll'
 
 function exec(cmd, value = null) {
   try {
@@ -265,6 +266,7 @@ export default function RichTextEditor({
       if (types.includes(SHINKAN_EXERCISE_MEDIA_DRAG_MIME)) {
         e.preventDefault()
         e.dataTransfer.dropEffect = 'copy'
+        autoScrollForDragNearEdges(e)
       }
     },
     [showInlineToolbar],

frontend/src/pages/ExerciseDetailPage.jsx

@@ -1,5 +1,5 @@
 import React, { useEffect, useState } from 'react'
-import { Link, useNavigate, useParams } from 'react-router-dom'
+import { Link, useNavigate, useParams, useLocation } from 'react-router-dom'
 import api from '../utils/api'
 import ExerciseRichTextBlock from '../components/ExerciseRichTextBlock'
 import ExerciseAttachmentMediaStrip from '../components/ExerciseAttachmentMediaStrip'
@@ -53,6 +53,7 @@ function metaParts(exercise) {
 function ExerciseDetailPage() {
   const { id } = useParams()
   const navigate = useNavigate()
+  const location = useLocation()
   const [exercise, setExercise] = useState(null)
   const [error, setError] = useState(null)
   const [loading, setLoading] = useState(true)
@@ -104,16 +105,19 @@ function ExerciseDetailPage() {
   if (!exercise) return null
 
   const meta = metaParts(exercise)
+  const fromExerciseEdit = location.state?.fromExerciseEdit === true
 
   return (
     <div className="exercise-detail-shell" style={{ padding: '12px 12px 24px' }}>
-      <div style={{ marginBottom: '12px', display: 'flex', justifyContent: 'space-between', gap: '8px', flexWrap: 'wrap' }}>
+      <div style={{ marginBottom: '12px', display: 'flex', justifyContent: 'space-between', gap: '8px', flexWrap: 'wrap', alignItems: 'center' }}>
         <button type="button" className="btn btn-secondary" onClick={() => navigate('/exercises')}>
           ← Übersicht
         </button>
-        <Link to={`/exercises/${exercise.id}/edit`} className="btn btn-primary">
-          Bearbeiten
-        </Link>
+        <div style={{ display: 'flex', flexWrap: 'wrap', gap: '8px', marginLeft: 'auto' }}>
+          <Link to={`/exercises/${exercise.id}/edit`} className="btn btn-primary">
+            {fromExerciseEdit ? 'Zurück zur Bearbeitung' : 'Bearbeiten'}
+          </Link>
+        </div>
       </div>
 
       <div className="card exercise-detail-section">

frontend/src/pages/ExerciseFormPage.jsx

@@ -9,6 +9,7 @@ import {
   SHINKAN_EXERCISE_MEDIA_DRAG_MIME,
   buildExerciseMediaDragPayload,
 } from '../utils/exerciseInlineMediaRefs'
+import { autoScrollForDragNearEdges } from '../utils/dragAutoScroll'
 import { SKILL_LEVEL_OPTIONS, normalizeSkillLevelSlug } from '../constants/skillLevels'
 import { useAuth } from '../context/AuthContext'
 
@@ -373,6 +374,7 @@ function ExerciseFormPage() {
   const [mediaList, setMediaList] = useState([])
   const [loading, setLoading] = useState(!!isEdit)
   const [saving, setSaving] = useState(false)
+  const [formDirty, setFormDirty] = useState(false)
   const [skillPick, setSkillPick] = useState('')
   const [variants, setVariants] = useState([])
   const [variantDraft, setVariantDraft] = useState(() => emptyVariantDraft())
@@ -385,7 +387,6 @@ function ExerciseFormPage() {
   const [mediaSavingId, setMediaSavingId] = useState(null)
   const [archiveOpen, setArchiveOpen] = useState(false)
   const [archiveQ, setArchiveQ] = useState('')
-  const [archiveCtx, setArchiveCtx] = useState('ablauf')
   const [archiveLoading, setArchiveLoading] = useState(false)
   const [archiveItems, setArchiveItems] = useState([])
   const [archiveError, setArchiveError] = useState(null)
@@ -396,12 +397,32 @@ function ExerciseFormPage() {
     for (const m of mediaList) {
       next[m.id] = {
         title: m.title || '',
-        context: m.context || 'ablauf',
       }
     }
     setMediaFields(next)
   }, [mediaList])
 
+  useEffect(() => {
+    const onDragOverDoc = (e) => {
+      const types = e.dataTransfer?.types ? Array.from(e.dataTransfer.types) : []
+      if (!types.includes(SHINKAN_EXERCISE_MEDIA_DRAG_MIME)) return
+      e.preventDefault()
+      autoScrollForDragNearEdges(e)
+    }
+    document.addEventListener('dragover', onDragOverDoc)
+    return () => document.removeEventListener('dragover', onDragOverDoc)
+  }, [])
+
+  useEffect(() => {
+    if (!formDirty) return undefined
+    const warn = (ev) => {
+      ev.preventDefault()
+      ev.returnValue = ''
+    }
+    window.addEventListener('beforeunload', warn)
+    return () => window.removeEventListener('beforeunload', warn)
+  }, [formDirty])
+
   useEffect(() => {
     if (!archiveOpen) return undefined
     let cancelled = false
@@ -466,6 +487,7 @@ function ExerciseFormPage() {
       setVariants([])
       setVariantDraft(emptyVariantDraft())
       setVariantEditSelection(null)
+      setFormDirty(false)
       setLoading(false)
       return
     }
@@ -480,6 +502,7 @@ function ExerciseFormPage() {
         setVariants((exercise.variants || []).map(apiVariantToRow))
         setVariantDraft(emptyVariantDraft())
         setVariantEditSelection(null)
+        setFormDirty(false)
       } catch (err) {
         if (!cancelled) {
           alert(err.message || 'Übung nicht ladbar')
@@ -509,6 +532,7 @@ function ExerciseFormPage() {
   }, [variantEditSelection])
 
   const updateFormField = (field, value) => {
+    setFormDirty(true)
     setFormData((prev) => ({ ...prev, [field]: value }))
   }
 
@@ -646,6 +670,7 @@ function ExerciseFormPage() {
         const ex = await api.getExercise(exerciseId)
         setMediaList(ex.media || [])
         setVariants((ex.variants || []).map(apiVariantToRow))
+        setFormDirty(false)
         alert('Gespeichert.')
       } else {
         const created = await api.createExercise(payload)
@@ -669,7 +694,7 @@ function ExerciseFormPage() {
     try {
       await api.attachExerciseMediaFromAsset(exerciseId, {
         media_asset_id: assetId,
-        context: archiveCtx,
+        context: 'ablauf',
         title: '',
         description: '',
         is_primary: false,
@@ -689,7 +714,8 @@ function ExerciseFormPage() {
   const handleDeleteMedia = async (mid) => {
     if (
       !confirm(
-        'Dieses Medium aus der Übung entfernen? Nur die Verknüpfung wird gelöscht. Die Datei bleibt im Archiv, solange sie noch woanders genutzt wird.',
+        'Dieses Medium aus der Übung entfernen? Nur die Verknüpfung wird gelöscht. Die Datei bleibt im Archiv, solange sie noch woanders genutzt wird.\n\n' +
+          'Hinweis: Wenn dieser Eintrag noch als Platzhalter im Fließtext steht, zeigt die Vorschau [Medium nicht verfügbar] oder das Speichern der Übung schlägt fehl, bis der Platzhalter entfernt ist.',
       )
     ) {
       return
@@ -740,7 +766,6 @@ function ExerciseFormPage() {
     try {
       await api.updateExerciseMedia(exerciseId, mid, {
         title: fld.title.trim() || null,
-        context: fld.context,
       })
       await refreshMedia()
     } catch (e) {
@@ -757,6 +782,7 @@ function ExerciseFormPage() {
   }
 
   const updateVariantField = (id, patch) => {
+    setFormDirty(true)
     setVariants((prev) => prev.map((v) => (v.id === id ? { ...v, ...patch } : v)))
   }
 
@@ -860,7 +886,18 @@ function ExerciseFormPage() {
             type="button"
             className="btn btn-secondary"
             style={{ marginLeft: '8px' }}
-            onClick={() => navigate(`/exercises/${exerciseId}`)}
+            onClick={() => {
+              if (
+                formDirty &&
+                !window.confirm(
+                  'Es gibt noch nicht über „Speichern“ gesicherte Änderungen (Texte, Zuordnungen, …).\n\n' +
+                    'Zur Ansicht wechseln und diese Änderungen verwerfen?',
+                )
+              ) {
+                return
+              }
+              navigate(`/exercises/${exerciseId}`, { state: { fromExerciseEdit: true } })
+            }}
           >
             Ansehen
           </button>
@@ -1236,7 +1273,10 @@ function ExerciseFormPage() {
                 <h3 style={{ marginTop: 0, fontSize: '1rem' }}>Neue Variante</h3>
                 <ExerciseVariantFields
                   row={variantDraft}
-                  onPatch={(patch) => setVariantDraft((d) => ({ ...d, ...patch }))}
+                  onPatch={(patch) => {
+                    setFormDirty(true)
+                    setVariantDraft((d) => ({ ...d, ...patch }))
+                  }}
                   prerequisiteOthers={variants}
                   rteMinHeight="110px"
                   inlineExerciseId={isEdit ? exerciseId : null}
@@ -1417,37 +1457,17 @@ function ExerciseFormPage() {
                         <input
                           type="text"
                           className="form-input exercise-edit-media-strip__title"
-                          placeholder="Titel"
+                          placeholder="Titel (wird in der Vorschau und im Platzhalter genutzt)"
                           value={(mediaFields[m.id] || {}).title ?? ''}
                           onChange={(e) =>
                             setMediaFields((prev) => ({
                               ...prev,
                               [m.id]: {
-                                ...(prev[m.id] || {}),
                                 title: e.target.value,
-                                context: (prev[m.id] || {}).context || 'ablauf',
                               },
                             }))
                           }
                         />
-                        <select
-                          className="form-input exercise-edit-media-strip__ctx"
-                          value={(mediaFields[m.id] || {}).context || 'ablauf'}
-                          onChange={(e) =>
-                            setMediaFields((prev) => ({
-                              ...prev,
-                              [m.id]: {
-                                ...(prev[m.id] || {}),
-                                title: (prev[m.id] || {}).title ?? '',
-                                context: e.target.value,
-                              },
-                            }))
-                          }
-                        >
-                          <option value="ablauf">Ablauf</option>
-                          <option value="detail">Detail</option>
-                          <option value="trainer_hint">Trainer-Hinweis</option>
-                        </select>
                       </div>
                       <div className="exercise-edit-media-strip__actions">
                         {mediaList.length > 1 && (
@@ -1498,6 +1518,10 @@ function ExerciseFormPage() {
               })}
             </ul>
           )}
+          <p style={{ color: 'var(--text3)', fontSize: '12px', marginTop: mediaList.length ? '12px' : 0 }}>
+            Verknüpfungen bleiben nötig (u. a. Zugriff, Orphan-Hinweise): Im Fließtext verweist du gezielt über
+            Platzhalter. Ohne Verknüpfung gäbe es keine exercise_media-ID zum Einbetten.
+          </p>
           {archiveOpen && (
             <div
               role="dialog"
@@ -1534,16 +1558,6 @@ function ExerciseFormPage() {
                   onChange={(e) => setArchiveQ(e.target.value)}
                   style={{ marginBottom: '8px' }}
                 />
-                <select
-                  className="form-input"
-                  value={archiveCtx}
-                  onChange={(e) => setArchiveCtx(e.target.value)}
-                  style={{ marginBottom: '12px' }}
-                >
-                  <option value="ablauf">Sektion: Ablauf</option>
-                  <option value="detail">Sektion: Detail</option>
-                  <option value="trainer_hint">Sektion: Trainer-Hinweis</option>
-                </select>
                 {archiveLoading && <p style={{ fontSize: '13px', color: 'var(--text3)' }}>Laden…</p>}
                 {archiveError && <p style={{ fontSize: '13px', color: 'var(--danger)' }}>{archiveError}</p>}
                 {!archiveLoading && !archiveError && archiveItems.length === 0 && (

frontend/src/utils/dragAutoScroll.js

@@ -0,0 +1,66 @@
+/**
+ * Während eines Drags automatischen Bildlauf auslösen (Viewport + scrollbare Bereiche unter dem Cursor).
+ * @param {DragEvent} e
+ * @param {{ edgePx?: number, scrollStep?: number }} [opts]
+ */
+export function autoScrollForDragNearEdges(e, opts = {}) {
+  const edge = opts.edgePx ?? 80
+  const step = opts.scrollStep ?? Math.max(24, Math.round(window.innerHeight * 0.05))
+  const { clientX, clientY } = e
+
+  const vh = window.innerHeight || 0
+  const vw = window.innerWidth || 0
+
+  let sy =
+    clientY < edge ? -step : vh > 0 && clientY > vh - edge ? step : 0
+  let sx =
+    clientX < edge ? -step : vw > 0 && clientX > vw - edge ? step : 0
+
+  if (sy !== 0) window.scrollBy(0, sy)
+  if (sx !== 0) window.scrollBy(sx, 0)
+
+  /** @type {HTMLElement|null} */
+  let top = /** @type {HTMLElement|null} */ (document.elementFromPoint(clientX, clientY))
+
+  /** @type {Set<HTMLElement>} */
+  const done = new Set()
+
+  /** @type {HTMLElement|null} */
+  let walk = top
+  const innerEdge = Math.min(edge, 40)
+
+  while (walk && walk !== document.body) {
+    if (!(walk instanceof HTMLElement)) break
+
+    const cs = window.getComputedStyle(walk)
+    const canY =
+      walk.scrollHeight - walk.clientHeight > 6 &&
+      (cs.overflowY === 'auto' || cs.overflowY === 'scroll')
+    const canX =
+      walk.scrollWidth - walk.clientWidth > 6 &&
+      (cs.overflowX === 'auto' || cs.overflowX === 'scroll')
+
+    if ((canY || canX) && !done.has(walk)) {
+      done.add(walk)
+      const rect = walk.getBoundingClientRect()
+
+      const relY = clientY - rect.top
+      const relX = clientX - rect.left
+
+      if (canY) {
+        if (relY < innerEdge && walk.scrollTop > 0) walk.scrollTop -= step
+        else if (rect.height - relY < innerEdge && walk.scrollTop < walk.scrollHeight - walk.clientHeight) {
+          walk.scrollTop += step
+        }
+      }
+      if (canX) {
+        if (relX < innerEdge && walk.scrollLeft > 0) walk.scrollLeft -= step
+        else if (rect.width - relX < innerEdge && walk.scrollLeft < walk.scrollWidth - walk.clientWidth) {
+          walk.scrollLeft += step
+        }
+      }
+    }
+
+    walk = walk.parentElement
+  }
+}