refactor(file-upload): scope prompt binding rollback

packages/api/session-controller/src/commands.ts

@@ -341,14 +341,10 @@ export class SessionCommandController {
             { sessionId: agent.id },
           )
         }
-        const rollback = this.ctx.fileUploads.bindPrompt(agent, durable.receiptIds, request.requestId)
-        try {
-          if (request.mode === 'steer') agent.steer(message)
-          else agent.followup(message)
-        } catch (error) {
-          rollback()
-          throw error
-        }
+        using binding = this.ctx.fileUploads.bindPrompt(agent, durable.receiptIds, request.requestId)
+        if (request.mode === 'steer') agent.steer(message)
+        else agent.followup(message)
+        binding.commit()
       } catch (error) {
         if (remoteErrorOf(error) !== undefined) throw error
         if (error instanceof AttachmentError) {

packages/api/session-controller/tests/controller.host.spec.ts

@@ -49,7 +49,7 @@ describe('SessionController facade', () => {
         return () => {}
       },
       resolve: () => undefined,
-      bindPrompt: () => () => {},
+      bindPrompt: () => ({ commit: () => {}, [Symbol.dispose]: () => {} }),
       retirePrompt: () => {},
     } as never)
     const controller = createSessionTestController(ctx, defaults)

packages/api/session-controller/tests/test-remote.ts

@@ -240,7 +240,7 @@ function installControllers(
     ctx.provide('fileUploads', {
       registerAgentResolver: () => () => {},
       resolve: () => undefined,
-      bindPrompt: () => () => {},
+      bindPrompt: () => ({ commit: () => {}, [Symbol.dispose]: () => {} }),
       retirePrompt: () => {},
     } as never)
   }