Constant-tag `Dynamic` / `dynamic()` should take the compiled-element path

[ryansolid]

Version: 2.0.0-rc.8 (@solidjs/web), packages/web/src/index.ts ~282–381 and index.server.ts ~81–142

dynamic(() => "button") — a string tag that can never change — still allocates a factory memo over source, a per-instance memo, and on the client goes through createElement + a full spread. That's the cost @yak/solid measured its way out of by reimplementing the element path from template/getNextElement/spread/insert (createElementRenderer in next-yak#644), i.e. by hand-writing what the compiler emits for <button {...props}>.

Proposal

When source is a string (or Dynamic's component is a non-reactive string):

1. No memos. Resolve the tag once at factory time; the per-instance function returns the element directly. Hydration ids stay aligned because no owner is created on either side (the server path mirrors it).
2. Template + static class. Accept a static class (and other static attrs) to bake into a cached template() like compiled JSX does, so the per-instance work is clone + getNextElement + reactive bindings only.
3. Compiled-element semantics. Call runHydrationEvents() after binding (missing today, see dynamic() / Dynamic with a string tag: no runHydrationEvents(), namespace ignores parent #3386), and take the namespace from the mount context or an explicit option instead of SVGElements.has(tag) alone (see dynamic() / Dynamic with a string tag: no runHydrationEvents(), namespace ignores parent #3386).
4. Keep the existing memo path for function/async sources; the string branch is a fast path, not a behavior change.

Tracker: #3389.

Public shape is open: either dynamic() detects it, or a small explicit primitive (element(tag, props, { class })) that libraries with a runtime styled() API can target. The second is what yak actually needed.

Measured

ryansolid/yak-bench: yak's base runtime rendered every styled element through Dynamic and sits at 0.65× React on SSR and ~2× slower than the PR on hydrate/mount; the PR's hand-rolled element path is 25× React on SSR for static tags. Acceptance for this issue: a yak-runtime variant that uses the new path instead of createElementRenderer lands within noise of it on compose-1 / button-variants-nested / btn-variant.