feat(registry): bring back the video-primitive moves (#3169)

Restores the 208 catalog items reverted after their previews 404'd in
production, this time on the payload mechanism rather than the .html files
that caused the outage.

The generator no longer writes a preview document to docs/public. That writer,
and the machinery under it, existed only to produce files the docs host
discards, so it is gone rather than bypassed. Items now embed the composition
itself via a payload, which is what the previous change already does for the
items that were already in the catalog.

The variables explorer is parked, not restored: it drove its preview through
the same unpublished .html path, so it would have shown an empty frame. Items
that declare variables get the live player plus the static variables table, and
reconnecting the explorer to payloads is a follow-up.

registry/components/tilt-card/registry-item.json

@@ -0,0 +1,80 @@
+{
+  "$schema": "https://hyperframes.heygen.com/schema/registry-item.json",
+  "name": "tilt-card",
+  "type": "hyperframes:component",
+  "title": "Tilt Card",
+  "description": "A transitions.dev-inspired tilt card primitive with depth layers and hover-style parallax",
+  "tags": ["video-primitive", "transition-primitive", "transitions-dev-port", "card", "tilt"],
+  "files": [
+    {
+      "path": "tilt-card.html",
+      "target": "compositions/components/tilt-card.html",
+      "type": "hyperframes:snippet"
+    }
+  ],
+  "variables": [
+    {
+      "id": "eyebrow",
+      "type": "string",
+      "role": "content",
+      "label": "Eyebrow",
+      "description": "Small uppercase kicker above the headline.",
+      "default": "Primitive"
+    },
+    {
+      "id": "headline",
+      "type": "string",
+      "role": "content",
+      "label": "Headline",
+      "description": "Large card headline.",
+      "default": "Agent-ready motion"
+    },
+    {
+      "id": "glow",
+      "type": "enum",
+      "role": "motion",
+      "label": "Glow",
+      "description": "How far the corner glow reaches past the card edges, which sets both its spread at rest and how far the timeline drift carries it.",
+      "default": "standard",
+      "options": [
+        {
+          "value": "tight",
+          "label": "Tight"
+        },
+        {
+          "value": "standard",
+          "label": "Standard"
+        },
+        {
+          "value": "wide",
+          "label": "Wide"
+        }
+      ]
+    },
+    {
+      "id": "accent",
+      "type": "enum",
+      "role": "style",
+      "label": "Accent",
+      "description": "Colour family of the card gradient, corner glow, eyebrow and drop shadow.",
+      "default": "indigo",
+      "options": [
+        {
+          "value": "indigo",
+          "label": "Indigo"
+        },
+        {
+          "value": "emerald",
+          "label": "Emerald"
+        },
+        {
+          "value": "violet",
+          "label": "Violet"
+        }
+      ]
+    }
+  ],
+  "preview": {
+    "poster": "https://static.heygen.ai/hyperframes-oss/docs/images/catalog/components/tilt-card.png"
+  }
+}