feat(tui): show required operator input at the composer

docs/TUI.md

@@ -29,7 +29,8 @@ terminal with nothing optional showing, the transcript floor is 12 rows
 (`IDLE_TRANSCRIPT_FLOOR`); with an inset overlay open the floor drops to 8 rows (`OVERLAY_TRANSCRIPT_FLOOR`) so the log stays glanceable
 underneath a permission prompt. When space is scarce, collapse follows a
 fixed order — transient banners first, then settings/plugin notices, then
-task/agents strips, then progress, then the prompt itself shrinks one
+task/agents strips, then progress, then the INPUT REQUIRED strip (the last
+optional row), then the prompt itself shrinks one
 row at a time down to its 3-row base — never the transcript
 (`COLLAPSE_ORDER` in `zones.ts`).
 
@@ -331,6 +332,31 @@ truncates first, then requester metadata and routing copy shorten, while the
 waiting label and the count stay. Primary-session `ask_operator` prompts keep
 their own overlay and never use this strip.
 
+### INPUT REQUIRED strip
+
+While a primary-session `ask_operator` question is unanswered, a one-row
+**INPUT REQUIRED** strip sits on the prompt box (zone `input_required`):
+
+```
+◆ INPUT REQUIRED · operator answer needed · Which environment should I deploy to? (+1 more)
+```
+
+It keeps the owed answer in view while the operator scrolls, types, or has
+the operator modal open. It is display only: the modal stays the one place
+to answer, and the strip never changes focus, key routing, overlay order,
+timeouts, or cancellation. Only gates the primary session's `ask_operator`
+callback marks with `source: "primary-ask-operator"` raise it; permission
+gates, MCP-trust gates, and worker `ask_director` questions never do. An
+item's identity is its gate id, and it leaves when that gate settles
+(answered, cancelled with Esc, timed out, aborted, or torn down); host
+dispose clears every item (`src/tui/operator-input-required.ts`, fed from
+`gate-wire.ts` and painted by `paintChrome` in `shell/chrome.ts`). One
+question shows at a time, with `(+N more)` for the rest. At narrow widths the
+question truncates and then drops first, then the routing copy. Below 26
+cells the `(+N more)` count is sliced away (cut at 25, gone at 16), leaving
+only the label. When WORKER WAITING is also showing, it sits directly above
+this strip.
+
 ### Transcript spawn_agent rows (history anchors)
 
 `runtime-bridge` paints each `spawn_agent` call as a transcript stream row for

src/tui/gate-events.ts

@@ -4,6 +4,11 @@ import type {
 } from "../permission/types.js";
 import type { OperatorResult } from "../agent/tools.js";
 
+/** Provenance minted only by the primary session's ask_operator callback. */
+export const PRIMARY_ASK_OPERATOR_SOURCE = "primary-ask-operator" as const;
+
+export type OperatorGateSource = typeof PRIMARY_ASK_OPERATOR_SOURCE;
+
 /** Fail-closed settle when no approval UI can bind the operator's accept. */
 export const APPROVAL_UNAVAILABLE_MESSAGE =
   "no approval UI available; request denied" as const;
@@ -27,6 +32,18 @@ export interface OperatorGateEvent {
    * queue — the modal cannot outlive a tool that already finished.
    */
   signal?: AbortSignal;
+  /**
+   * Optional display provenance minted by the session emitter, never inferred
+   * from an operator question by the TUI.
+   */
+  source?: OperatorGateSource;
+}
+
+/** Only an explicitly marked primary ask may enter input-required chrome. */
+export function isPrimaryAskOperatorEvent(
+  event: OperatorGateEvent,
+): event is OperatorGateEvent & { readonly source: OperatorGateSource } {
+  return event.source === PRIMARY_ASK_OPERATOR_SOURCE;
 }
 
 export interface PermissionGateEvent {