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the same unpublished .html path, so it would have shown an empty frame.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/before-after-wipe/registry-item.json

@@ -0,0 +1,88 @@
+{
+  "$schema": "https://hyperframes.heygen.com/schema/registry-item.json",
+  "name": "before-after-wipe",
+  "type": "hyperframes:component",
+  "title": "Before After Wipe",
+  "description": "Two full-bleed content slots compare before and after states as a persistent divider wipes the after layer over the before layer and rests at a configurable split. Callers fill the named before/after slot panels; token-styled defaults render when a slot is left empty.",
+  "tags": ["prop", "ui-props", "compare", "holdable", "before-after", "wipe", "slots"],
+  "jobs": ["compare"],
+  "family": "ui-props",
+  "profile": "holdable",
+  "evidence": "Wave J U-B: comparison-split divider-wipe mechanic ported onto real content slots",
+  "syncPoints": [{ "id": "wipe-land", "phase": "in", "offset": 1.3 }],
+  "files": [
+    {
+      "path": "before-after-wipe.html",
+      "target": "compositions/components/before-after-wipe.html",
+      "type": "hyperframes:snippet"
+    }
+  ],
+  "variables": [
+    {
+      "id": "label_a",
+      "type": "string",
+      "role": "content",
+      "label": "Before label",
+      "description": "Chip shown on the base before panel. Blank hides the chip.",
+      "default": "Before"
+    },
+    {
+      "id": "label_b",
+      "type": "string",
+      "role": "content",
+      "label": "After label",
+      "description": "Chip shown on the revealed after panel. Blank hides the chip.",
+      "default": "After"
+    },
+    {
+      "id": "rest_split",
+      "type": "number",
+      "role": "layout",
+      "label": "Resting split",
+      "description": "Divider resting position after the wipe lands.",
+      "default": 50,
+      "min": 0,
+      "max": 100,
+      "step": 1,
+      "unit": "%"
+    },
+    {
+      "id": "wipe_at",
+      "type": "number",
+      "role": "timing",
+      "label": "Wipe start",
+      "description": "Seconds after mount start when the wipe begins.",
+      "default": 0.25,
+      "min": 0,
+      "max": 8,
+      "step": 0.05,
+      "unit": "s"
+    },
+    {
+      "id": "accent",
+      "type": "enum",
+      "role": "style",
+      "label": "Accent",
+      "description": "Divider handle and after chip color.",
+      "default": "green",
+      "options": [
+        { "value": "green", "label": "Green" },
+        { "value": "blue", "label": "Blue" },
+        { "value": "violet", "label": "Violet" }
+      ]
+    },
+    {
+      "id": "exit",
+      "type": "enum",
+      "role": "timing",
+      "label": "Exit",
+      "description": "Outgoing transition. None holds the final comparison frame.",
+      "default": "none",
+      "options": [
+        { "value": "none", "label": "None" },
+        { "value": "fade", "label": "Fade" },
+        { "value": "up", "label": "Up" }
+      ]
+    }
+  ]
+}