feat(web): steer queued messages into active turns

packages/host/apiproxy/src/api/rpc.schema.ts

@@ -48,6 +48,7 @@ export const rpcErrorSchema: z.ZodType<RpcError> = z.discriminatedUnion('code',
   z.object({ code: z.literal('directory-picker-unavailable'), message: z.string(), details: z.object({ capability: z.string() }) }),
   z.object({ code: z.literal('agent-busy'), message: z.string(), details: z.object({ reason: z.string() }) }),
   z.object({ code: z.literal('queue-item-not-found'), message: z.string(), details: z.object({ itemId: z.string() }) }),
+  z.object({ code: z.literal('steer-unavailable'), message: z.string(), details: z.object({ itemId: z.string() }) }),
   z.object({ code: z.literal('command-error'), message: z.string(), details: z.object({}) }),
   z.object({ code: z.literal('unknown-command'), message: z.string(), details: z.object({}) }),
   z.object({ code: z.literal('settings-rejected'), message: z.string(), details: z.object({ ns: z.string() }) }),

packages/host/apiproxy/src/api/rpc.ts

@@ -46,6 +46,7 @@ export interface RpcErrorDetailsMap {
   'directory-picker-unavailable': { capability: string }
   'agent-busy': { reason: string }
   'queue-item-not-found': { itemId: InboxItemId }
+  'steer-unavailable': { itemId: InboxItemId }
   /** A known slash command reported a usage/state error; the message is the command's own text. */
   'command-error': {}
   /** A leading-/ prompt named no registered command; the message names the token. */

packages/host/apiproxy/src/api/sessions.schema.ts

@@ -269,6 +269,7 @@ export const sessionUpdateQueueRequestSchema = z.object({
   action: z.discriminatedUnion('kind', [
     z.object({ kind: z.literal('edit'), content: z.array(contentBlockSchema) }),
     z.object({ kind: z.literal('remove') }),
+    z.object({ kind: z.literal('steer') }),
   ]),
 }) as unknown as z.ZodType<RequestPayload<'session.updateQueue'>>
 

packages/host/apiproxy/src/api/sessions.ts

@@ -129,6 +129,7 @@ export interface SessionModels {
 export type QueueAction =
   | { kind: 'edit'; content: ContentBlock[] }
   | { kind: 'remove' }
+  | { kind: 'steer' }
 
 /** Session list entry (v1 builds no index: list does readdir+stat). */
 export interface SessionSummary {
@@ -285,7 +286,7 @@ export interface SessionsApi {
   Promise<RpcResponse<{ accepted: true; command?: { kind: 'success'; text?: string } }>>
 
   /**
-   * Edits or removes one pending queued occurrence on an ordinary session.
+   * Edits, removes, or strictly steers one pending queued occurrence on an ordinary session.
    * Session-backed subagents reject with `agent-busy`.
    */
   updateQueue(request: RpcRequest<{ sessionId: SessionId; itemId: InboxItemId; action: QueueAction }>):