feat(registry): add caret swap text effect

[AksharP5]

What

Adds Caret Swap: a gradient caret covers one phrase, collapses left, then types its replacement. Use it for a correction, punchline, or before-and-after statement.

Fixes #3897.

1280×720, 30 fps render:

caret-swap.mp4

How

A paused GSAP timeline provides measured centering and grapheme-aware typing. Both phrases, font size and weight, text color, and gradient endpoints are Catalog variables. Text shrinks to fit; short mounts compress the phases and longer mounts extend the final hold.

Geist is bundled with its OFL license. The component retains Remocn's MIT notice and pinned source attribution. Visual reference.

This PR contains the component sources and the authored-demo preference that preserves its light background. It follows the current source-only catalog workflow: CI generates the docs, previews and search index; the catalog publication PR makes the item discoverable. After publication, install with npx hyperframes add caret-swap.

Validation

• 195 focused Catalog/publication tests pass.
• Component registry lint, scripts typecheck, formatting and Fallow pass.
• The generated Caret Swap payload loads without failed requests or page errors.
• Existing render and installation checks remain applicable; the component source is unchanged by the main sync.

The full local typecheck hook is blocked by missing Studio dependencies in this worktree. Studio matches main exactly; CI runs with the current dependency set. The embedding model was not downloaded locally, as requested; CI handles index generation.