## Summary
Adds `offsetX`, `offsetY`, `movementX`, `movementY` to
`SerializedEventData` and the host event serialiser so apps can reason
about element-relative pointer positions without trying to read the host
element's bounding rect (which is impossible from a remote-DOM worker).
## Motivation
I was building a front-component with click-to-drop-pin and trackpad
pan/zoom (custom OSM tile renderer). Two real bugs surfaced from the
current event-serialisation surface:
1. **Wheel pan/zoom was broken.** The host already forwards
`deltaX`/`deltaY`, but app authors naturally read them off the
React-style event handler argument as `e.deltaX`/`e.deltaY`. Because
remote-DOM bridges everything via `RemoteEvent extends
CustomEvent<Detail>`, the payload actually arrives at `e.detail.deltaX`.
Reading the wrong place gives `undefined`, and `undefined < 0 ===
false`, so every wheel notch zoomed in the same direction. App code now
uses `e.detail`, but this was a sharp papercut worth flagging in docs /
a helper (separate change).
2. **Element-local click coords are unobtainable from a worker.** With
only `clientX/Y`, an app needs the stage's bounding rect to translate
viewport coordinates to local — which can't be read across the worker
boundary. `offsetX`/`offsetY` close that gap with a one-read solution.
`movementX`/`movementY` round out the set for any future drag-style
interactions if `mousemove` later joins the allow-list.
- Add 72 missing HTML and SVG elements to the remote-dom component
registry (48 HTML + 24 SVG), bringing the total from 47 to 119 supported
elements
- HTML additions include semantic inline text (b, i, u, s, mark, sub,
sup, kbd, etc.), description lists, ruby annotations, structural
elements (figure, details, dialog), and form utilities (fieldset,
progress, meter, optgroup)
- SVG additions include containers (svg, g, defs), shapes (path, circle,
rect, line, polygon), text (text, tspan), gradients (linearGradient,
radialGradient, stop), and utilities (clipPath, mask, foreignObject,
marker)
- Add htmlTag override to support SVG elements with camelCase names
(e.g. clipPath, foreignObject) while keeping custom element tags
lowercase per the Web Components spec
