## What
Add 28 transition blocks from the Hyperframe Template Structure catalog, bringing the registry to 53 total items.
### Shader transitions (14 blocks, WebGL, 4s each)
`domain-warp-dissolve`, `ridged-burn`, `whip-pan`, `sdf-iris`, `ripple-waves`, `gravitational-lens`, `cinematic-zoom`, `chromatic-radial-split`, `glitch`, `swirl-vortex`, `thermal-distortion`, `flash-through-white`, `cross-warp-morph`, `light-leak`
### CSS transition showcases (14 blocks, various durations)
`transitions-3d`, `transitions-blur`, `transitions-cover`, `transitions-destruction`, `transitions-dissolve`, `transitions-distortion`, `transitions-grid`, `transitions-light`, `transitions-mechanical`, `transitions-other`, `transitions-push`, `transitions-radial`, `transitions-scale`, `transitions-shader`
## Why
Phase D content accumulation. Transitions are the most-requested category for the catalog.
## How
- Shader transitions extracted from `shader-showcase.zip`, each a standalone HTML with WebGL shaders
- CSS transitions extracted from `showcase-bundle.zip`, each a standalone showcase page
- All tagged with `transition` + `shader` or `showcase` for catalog grouping
- Preview thumbnails generated for all 28 blocks
- Catalog pages + index regenerated
## Test plan
- [x] All 28 blocks produce preview thumbnails
- [x] `registry-item.json` validates for all blocks
- [x] Catalog pages generated (45 total items in catalog-index.json)
- [x] `oxfmt --check` passes
Extract three standalone blocks from existing example templates:
- data-chart: Animated bar + line chart with staggered reveal (from nyt-graph)
- flowchart: Decision tree with SVG connectors and cursor interaction (from decision-tree)
- logo-outro: Cinematic logo reveal with tagline and URL pill (from product-promo)
Each block is a complete HTML composition installable via `hyperframes add <name>`.
Blocks render as iframes in host compositions.
James Russo