feat(client): inject slot declaration lifetimes

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

@@ -148,12 +148,10 @@ export function apply(ctx: ClientContext): void {
   })
 
   // Entry 2: the composer's named model seat over the SAME directory.
-  // Conditional mount: the seat is declared by the composer-bar entry; the
-  // conversation service's presence is the registration-safe signal.
-  ctx.inject(['slots', 'conversation', 'models'], (scope: ClientContext) => {
+  ctx.inject(['slots', 'models'], (scope: ClientContext) => {
     const models = scope.models
     const sessions = scope.sessions
-    scope.effect(() => scope.slots.register({
+    scope.slots.inject('conversation.input.model', () => scope.slots.register({
       name: 'conversation.input.model',
       locale: NS,
       inject: (sessionId): ModelSelectInjected => {
@@ -170,6 +168,6 @@ export function apply(ctx: ClientContext): void {
             : Promise.resolve(false),
         }
       },
-    }, ModelSelect), 'ui-model: composer model seat registration')
+    }, ModelSelect))
   })
 }

packages/client/ui-model/tests/browser-plugin.spec.ts

@@ -85,12 +85,12 @@ async function bench() {
     locale: string | undefined
   }>()
   ctx.provide('slots', {
+    inject(_name: string, callback: () => () => void) { return callback() },
     register(options: { name: string; locale?: string; inject?: (sessionId: SessionId) => ModelSelectInjected }) {
       seats.set(options.name, { inject: options.inject, locale: options.locale })
       return () => { seats.delete(options.name) }
     },
   })
-  ctx.provide('conversation', {})
   ctx.provide('locale', new LocaleService(ctx))
   const scopes = new Map<SessionId, Context>()
   const addressed = new Set<SessionId>()