Migrate GM action button injection from imperative DOM manipulation to
a reactive Solid component (`RevealManager`) using `Portal`. This
improves cleanup reliability and ensures buttons are proper Solid
components rather than raw HTML strings injected into the DOM.
Also adds URI encoding for link paths and simplifies the reveal
store logic.
Decouple the reveal logic from the `Article` component by introducing
a `RevealManager` component and an `ArticleDomCtx`. This allows the
reveal logic to reactively manage DOM injections and classes without
polluting the `Article` component's props or lifecycle.
Additionally, implements a robust `cleanupInjections` mechanism to
ensure that injected buttons and styling artifacts are properly removed
during navigation, role changes, or disconnections.
hypercross