feat(remotion): craft kit (stop-motion + paper-cut) + PaperCut block

The real visible quality leap — a handmade craft aesthetic code can't fake by being
smooth:
- craft.ts: useStopMotion (quantize the frame to "on twos/threes" + per-step jitter
  → choppy handmade motion), paperShadow (layered cast shadows for paper depth),
  PAPER_TEXTURE (procedural fibrous paper grain).
- PaperCut block: a layered paper-cut landscape — sun + 4 brand-coloured paper hills
  with real cast shadows + paper grain, rising into place on stop-motion timing with
  an idle wobble, + paper-cut title/subtitle. Re-flows 16:9/1:1/9:16.

Registry now has 13 blocks. Verified: warm Yalda render (fits the Persian/seasonal
moat) + a stop-motion demo clip showing the on-threes choppy rise.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

services/remotion/src/scenes/registry.ts

@@ -11,6 +11,7 @@ import { BarChartBlock } from "./blocks/BarChart";
 import { StompBlock } from "./blocks/Stomp";
 import { DeviceMockupBlock } from "./blocks/DeviceMockup";
 import { ProductShowcaseBlock } from "./blocks/ProductShowcase";
+import { PaperCutBlock } from "./blocks/PaperCut";
 
 /**
  * The scene-block registry. A FlexStory template is an ordered list of these
@@ -30,6 +31,7 @@ export const SCENE_BLOCKS: Record<string, SceneBlock> = {
   [BarChartBlock.id]: BarChartBlock,
   [StompBlock.id]: StompBlock,
   [DeviceMockupBlock.id]: DeviceMockupBlock,
+  [PaperCutBlock.id]: PaperCutBlock,
 };
 
 export const BLOCK_LIST = Object.values(SCENE_BLOCKS);