feat(client): localize composer hints and rework input command interaction

Unify the /plan claimed hint with the plan placeholder through a locale
namespace, localize slash menu group titles, replace the PermissionSelect
native select with the Menu primitive, add a goal pause verb chain, clamp
anchored popups to the viewport with scroll-into-view and outside-dismiss,
and fix onPasteUpgrade insertedRange to account for the chip trailing gap.

packages/client/ui-skill/src/client/index.ts

@@ -100,6 +100,7 @@ export function apply(ctx: ClientContext): void {
   const source: SlashSource = {
     trigger: '/',
     name: 'skill',
+    order: 2,
     async candidates(session, { query, signal }) {
       const skills = await fetchCatalog(session.sessionId)
       // Superseded keystroke: the shared fetch stays warm, this caller yields.