Add videos: library, block and section background

Videos join the media library as their own table (schema v28), with a
video block and a looping background on sections. video.js starts loops
only while visible, offers a pause button and leaves the still image for
reduced motion and data saving.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01PWYm8kjAWmZaB2QB2xuBhU

public/assets/editor-model.js

@@ -1,5 +1,5 @@
-export const labels = { section: 'Sektion', row: 'Zeile', column: 'Spalte', heading: 'Überschrift', text: 'Text', image: 'Bild', button: 'Button', gallery: 'Galerie', postlist: 'Beitragsliste', postnav: 'Beitragsnavigation', iconcard: 'Symbolkarte', stat: 'Kennzahl', quote: 'Kundenstimme', logos: 'Logoleiste', cta: 'Aufruf-Band', contact: 'Kontaktdaten', divider: 'Trennlinie', spacer: 'Abstand', accordion: 'Akkordeon', accordionitem: 'Akkordeon-Eintrag', tabs: 'Tabs', tabitem: 'Tab', form: 'Formular', breadcrumb: 'Brotkrumen', menu: 'Navigation', partialref: 'Verknüpfte Sektion', embed: 'Externer Inhalt', icon: 'Symbol', progress: 'Fortschritt', slider: 'Slider', legal: 'Rechtszeile', social: 'Soziale Profile', html: 'Eigenes HTML', language: 'Sprachwahl' };
-export const icons = { section: '▣', row: '☰', column: '▥', heading: 'H', text: 'T', image: '▧', button: '↗', gallery: '▦', postlist: '☷', postnav: '⇄', iconcard: '◈', stat: '№', quote: '❝', logos: '⬚', cta: '◉', contact: '✆', divider: '—', spacer: '⇳', accordion: '⌵', accordionitem: '·', tabs: '▭', tabitem: '▫', form: '✉', breadcrumb: '⟩', menu: '☰', partialref: '⧉', legal: '§', embed: '⬓', icon: '◆', progress: '▰', slider: '⇄', social: '⚭', html: '</>', language: '文' };
+export const labels = { section: 'Sektion', row: 'Zeile', column: 'Spalte', heading: 'Überschrift', text: 'Text', image: 'Bild', video: 'Video', button: 'Button', gallery: 'Galerie', postlist: 'Beitragsliste', postnav: 'Beitragsnavigation', iconcard: 'Symbolkarte', stat: 'Kennzahl', quote: 'Kundenstimme', logos: 'Logoleiste', cta: 'Aufruf-Band', contact: 'Kontaktdaten', divider: 'Trennlinie', spacer: 'Abstand', accordion: 'Akkordeon', accordionitem: 'Akkordeon-Eintrag', tabs: 'Tabs', tabitem: 'Tab', form: 'Formular', breadcrumb: 'Brotkrumen', menu: 'Navigation', partialref: 'Verknüpfte Sektion', embed: 'Externer Inhalt', icon: 'Symbol', progress: 'Fortschritt', slider: 'Slider', legal: 'Rechtszeile', social: 'Soziale Profile', html: 'Eigenes HTML', language: 'Sprachwahl' };
+export const icons = { section: '▣', row: '☰', column: '▥', heading: 'H', text: 'T', image: '▧', video: '▶', button: '↗', gallery: '▦', postlist: '☷', postnav: '⇄', iconcard: '◈', stat: '№', quote: '❝', logos: '⬚', cta: '◉', contact: '✆', divider: '—', spacer: '⇳', accordion: '⌵', accordionitem: '·', tabs: '▭', tabitem: '▫', form: '✉', breadcrumb: '⟩', menu: '☰', partialref: '⧉', legal: '§', embed: '⬓', icon: '◆', progress: '▰', slider: '⇄', social: '⚭', html: '</>', language: '文' };
 // A namespaced type belongs to a plugin this installation may not have. Such blocks stay in the
 // document, stay selectable and movable, but the editor never edits or fills them.
 /**
@@ -9,7 +9,7 @@ export const icons = { section: '▣', row: '☰', column: '▥', heading: 'H',
  */
 export const CATEGORIES = [
   { name: 'Aufbau', hint: 'Sektion → Zeile → Spalte. Der Inhalt kommt in die Spalte.', types: ['section', 'row', 'column'] },
-  { name: 'Inhalt', types: ['heading', 'text', 'image', 'button', 'icon', 'divider', 'spacer'] },
+  { name: 'Inhalt', types: ['heading', 'text', 'image', 'video', 'button', 'icon', 'divider', 'spacer'] },
   { name: 'Bausteine', types: ['iconcard', 'stat', 'quote', 'cta', 'contact', 'social', 'logos', 'progress'] },
   { name: 'Gruppen', types: ['gallery', 'accordion', 'accordionitem', 'tabs', 'tabitem', 'slider'] },
   { name: 'Seite und Daten', types: ['postlist', 'postnav', 'breadcrumb', 'menu', 'language', 'form', 'legal', 'partialref', 'embed', 'html'] },
@@ -132,6 +132,8 @@ export function createBlock(type) {
   if (type === 'language') block.props = { display: 'code' };
   // Leer eingefuegt: nichts steht auf der Seite, bis jemand Code eintraegt.
   if (type === 'html') block.props = { html: '' };
+  // Leer eingefuegt wie „Eigenes HTML“: auf der Website steht nichts, bis ein Video gewaehlt ist.
+  if (type === 'video') block.props = { src: '', mode: 'player', title: '' };
   if (type === 'iconcard') block.props = { icon: 'check', title: 'Deine Leistung', text: 'Beschreibe hier kurz, worum es geht.', href: '' };
   if (type === 'stat') block.props = { value: '15+', label: 'Jahre Erfahrung' };
   if (type === 'quote') block.props = { text: 'Ein Satz, den eine Kundin oder ein Kunde über dich gesagt hat.', author: 'Name', role: '', rating: 5 };
@@ -197,6 +199,7 @@ export function upgradeForType(document, type) {
   if (type === 'postnav') upgradeDocument(document, 18);
   if (type === 'legal') upgradeDocument(document, 19);
   if (type === 'html') upgradeDocument(document, 24);
+  if (type === 'video') upgradeDocument(document, 28);
   if (type === 'language') upgradeDocument(document, 27);
   if (['iconcard', 'stat', 'quote', 'logos', 'cta', 'contact', 'divider', 'spacer', 'accordion', 'accordionitem'].includes(type)) upgradeDocument(document, 6);
   if (type === 'tabs' || type === 'tabitem') upgradeDocument(document, 7);
@@ -348,7 +351,7 @@ export const devices = { desktop: 'Desktop', tablet: 'Tablet', mobile: 'Mobil' }
 // blieb bei 12 stehen, während Bausteine schon v13 bis v15 verlangten: in einem aktuellen Dokument
 // liess sich dann gar nichts mehr einfügen, und ein Symbol, ein Slider oder ein externer Inhalt
 // nirgends. Eine Zahl, an einer Stelle.
-export const SCHEMA_VERSION = 27;
+export const SCHEMA_VERSION = 28;
 
 export const VISIBILITY = { all: 'Auf allen Geräten', desktop: 'Nur Desktop', tablet: 'Nur Tablet', mobile: 'Nur Mobil', 'hide-desktop': 'Auf Desktop ausblenden', 'hide-tablet': 'Auf Tablet ausblenden', 'hide-mobile': 'Auf Mobil ausblenden', hidden: 'Überall ausblenden' };
 
@@ -692,7 +695,7 @@ export function relevantProperty(block, key, property) {
   if (property.group === 'menu') return block.type === 'menu';
   if (property.group === 'icon') return block.type === 'button' && block.props?.icon !== 'none';
   if (property.group === 'image') return ['image', 'gallery', 'logos', 'postlist'].includes(block.type);
-  if (property.group === 'text' || key === 'textShadow') return !['image', 'gallery', 'logos', 'spacer', 'divider', 'embed'].includes(block.type);
+  if (property.group === 'text' || key === 'textShadow') return !['image', 'video', 'gallery', 'logos', 'spacer', 'divider', 'embed'].includes(block.type);
   if (key === 'columnWidths') return block.type === 'row';
   if (['flexDirection', 'flexWrap', 'justifyContent', 'alignItems', 'gridColumns', 'gap', 'rowGap', 'columnGap'].includes(key)) return container || ['button', 'menu', 'form', 'postlist', 'contact', 'social'].includes(block.type);
   return true;