feat: enhance canvas functionality with scissors mode and node template updates

- Implemented visual feedback and cursor changes for scissors mode in dark and light themes, improving user interaction during edge manipulation.
- Updated node template picker to include new keywords for AI image generation, enhancing searchability.
- Renamed and categorized node types for clarity, including updates to asset and prompt nodes.
- Added support for video nodes and adjusted related components for improved media handling on the canvas.

lib/pexels-types.ts

@@ -0,0 +1,81 @@
+export interface PexelsVideoFile {
+  id: number;
+  /** Pexels liefert u. a. `hls` mit `.m3u8` — nicht für `<video src>`. */
+  quality: "hd" | "sd" | "uhd" | "hls";
+  file_type: string;
+  width: number;
+  height: number;
+  fps: number;
+  link: string;
+}
+
+export interface PexelsVideo {
+  id: number;
+  width: number;
+  height: number;
+  url: string;
+  image: string;
+  duration: number;
+  user: {
+    id: number;
+    name: string;
+    url: string;
+  };
+  video_files: PexelsVideoFile[];
+}
+
+export interface VideoNodeData {
+  canvasId?: string;
+  pexelsId?: number;
+  mp4Url?: string;
+  thumbnailUrl?: string;
+  width?: number;
+  height?: number;
+  duration?: number;
+  attribution?: {
+    userName: string;
+    userUrl: string;
+    videoUrl: string;
+  };
+}
+
+function isProgressiveMp4Candidate(f: PexelsVideoFile): boolean {
+  if (f.quality === "hls") return false;
+  const url = f.link.toLowerCase();
+  if (url.includes(".m3u8")) return false;
+  return url.includes(".mp4");
+}
+
+/**
+ * Progressive MP4 für HTML5-`<video>` — niemals HLS/m3u8 (API setzt dort teils fälschlich `video/mp4`).
+ */
+export function pickVideoFile(files: PexelsVideoFile[]): PexelsVideoFile {
+  const playable = files.filter(isProgressiveMp4Candidate);
+  if (playable.length === 0) {
+    throw new Error("Kein MP4-Download von Pexels verfügbar (nur HLS?).");
+  }
+  return (
+    playable.find((f) => f.quality === "hd") ??
+    playable.find((f) => f.quality === "uhd") ??
+    playable.find((f) => f.quality === "sd") ??
+    playable[0]
+  );
+}
+
+/**
+ * Kleinste sinnvolle MP4 für Raster-Vorschau (bevorzugt SD, sonst kleinste Auflösung).
+ */
+export function pickPreviewVideoFile(files: PexelsVideoFile[]): PexelsVideoFile | null {
+  const playable = files.filter(isProgressiveMp4Candidate);
+  if (playable.length === 0) return null;
+  const sd = playable.filter((f) => f.quality === "sd");
+  const pool = sd.length > 0 ? sd : playable;
+  return pool.reduce((best, f) => {
+    const a = (f.width || 0) * (f.height || 0);
+    const b = (best.width || 0) * (best.height || 0);
+    if (a === 0 && b === 0) return f;
+    if (a === 0) return best;
+    if (b === 0) return f;
+    return a < b ? f : best;
+  });
+}