feat(projects): video de rolagem na capa dos cards, carregado so quando o card aparece

video autoplay muted loop playsinline preload=none com poster; as fontes entram
via IntersectionObserver e o video pausa fora da tela. Com prefers-reduced-motion
aparece so o poster.

Co-Authored-By: Claude Sonnet 5.5 <[email protected]>

lib/project-videos.ts

@@ -0,0 +1,34 @@
+/**
+ * Vídeos de rolagem dos projetos: public/videos/<id>/desktop.{webm,mp4,webp}.
+ * Gravados com scripts/record-project-videos.mjs; só entram aqui os ids que têm os três arquivos.
+ */
+export interface ProjectVideoAsset {
+  poster: string;
+  width: number;
+  height: number;
+  sources: Array<{ src: string; type: string }>;
+}
+
+export const PROJECT_VIDEO_IDS = [
+  "sev-modaintima",
+  "lavacao-047",
+  "nutriscan",
+  "sc-plus",
+  "as-servicos",
+] as const;
+
+const recorded = new Set<string>(PROJECT_VIDEO_IDS);
+
+export function getProjectVideo(id: string): ProjectVideoAsset | undefined {
+  if (!recorded.has(id)) return undefined;
+  const base = `/videos/${id}/desktop`;
+  return {
+    poster: `${base}.webp`,
+    width: 1440,
+    height: 900,
+    sources: [
+      { src: `${base}.webm`, type: 'video/webm; codecs="vp9"' },
+      { src: `${base}.mp4`, type: "video/mp4" },
+    ],
+  };
+}