feat: command.execute returns the lifecycle pairing id ({matched, commandId?})

CommandService.execute now returns a CommandExecution — the normalized
result plus the commandId minted for its command/run/command/done records —
and the wire admission value carries commandId exactly when matched, so the
issuing client can correlate its RPC acknowledgment with the flow node the
lifecycle events produce. apiproxy api/schema/handler, the connection
fixture, and the TUI/plan/goal consumers follow the new shape.

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

@@ -32,7 +32,8 @@ export const commandExecuteRequestSchema = z.object({
   line: z.string(),
 }) satisfies z.ZodType<Wire<RequestPayload<'command.execute'>>>
 
-/** command.execute response value: pure admission — outcomes ride the logged lifecycle events, never this response. */
+/** command.execute response value: pure admission — outcomes ride the logged lifecycle events; commandId (present exactly when matched) correlates with them. */
 export const commandExecuteValueSchema = z.object({
   matched: z.boolean(),
+  commandId: z.string().min(1).optional(),
 }) satisfies z.ZodType<Wire<ResponseValue<'command.execute'>>>

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

@@ -36,10 +36,12 @@ export interface CommandsApi {
    * when syntax or name does not resolve (the client falls back to its
    * default sink). The handler's outcome does NOT ride the response: the host
    * executor durably logs the lifecycle (`command/run`/`command/done`), which
-   * broadcasts on the mux stream and renders as a persistent flow node. The
-   * signal rides beside the request, never on the wire: the fetch carrier's
-   * request signal cancels the running handler.
+   * broadcasts on the mux stream and renders as a persistent flow node.
+   * `commandId` is present exactly when matched — the minted lifecycle
+   * pairing id, letting the issuing client correlate this acknowledgment
+   * with that flow node. The signal rides beside the request, never on the
+   * wire: the fetch carrier's request signal cancels the running handler.
    */
   execute(request: RpcRequest<{ sessionId: SessionId; line: string }>, signal: AbortSignal):
-  Promise<RpcResponse<{ matched: boolean }>>
+  Promise<RpcResponse<{ matched: boolean; commandId?: string }>>
 }