fix(registry): add missing vscode-theme-visualizer to registry.json

[Dashsoap]

What

Add the missing vscode-theme-visualizer entry to the auto-generated top-level registry/registry.json.

Why

The vscode-theme-visualizer example ships a complete manifest at registry/examples/vscode-theme-visualizer/registry-item.json (added in v0.6.104), along with its index.html, DESIGN.md, assets/, render-entries/, and scripts/. But it was never added to registry/registry.json.

The CLI resolver only knows about items listed in the top-level manifest — resolveItemWithDependencies() in packages/cli/src/registry/resolver.ts does entries.find((e) => e.name === name) and throws Item "..." not found in registry when there's no match. So hyperframes add vscode-theme-visualizer fails even though the item is fully present on disk.

All 9 example directories that carry a registry-item.json should appear in registry.json; before this change only 8 did:

registry examples in manifest: 8   ← missing vscode-theme-visualizer
example dirs with a manifest:  9

How

Added the one missing entry in the example block, right after nyt-graph:

{
  "name": "vscode-theme-visualizer",
  "type": "hyperframes:example"
},

This is exactly what re-running scripts/generate-registry-items.ts produces — its scanExistingItems() fallback picks up every example dir that has a registry-item.json, so the hand-applied entry matches the generator output and the manifest is back in sync (9/9).

Test plan

• Unit tests added/updated
• Manual testing performed — confirmed JSON.parse succeeds, item count 130 → 131, and the manifest's hyperframes:example set now exactly equals the set of example dirs that have a registry-item.json (was 8/9, now 9/9). Verified the entry matches what generate-registry-items.ts would emit.
• Documentation updated (if applicable)

[miguel-heygen]

@Dashsoap sign the commit to merge it pls

[Dashsoap]

Done — the commit is now signed and shows as Verified. Ready to merge whenever you get a chance. Thanks for the review!