feat(coding-agent): complete steer()/followUp() migration

- Update settings-manager with steeringMode/followUpMode (migrates old queueMode)
- Update sdk.ts to use new mode options
- Update settings-selector UI to show both modes
- Add Alt+Enter keybind for follow-up messages
- Update RPC API: steer/follow_up commands, set_steering_mode/set_follow_up_mode
- Update rpc-client with new methods
- Delete dead code: queue-mode-selector.ts
- Update tests for new API
- Update mom/context.ts stubs
- Update web-ui example

packages/coding-agent/src/modes/interactive/components/custom-editor.ts

@@ -1,5 +1,6 @@
 import {
 	Editor,
+	isAltEnter,
 	isCtrlC,
 	isCtrlD,
 	isCtrlG,
@@ -28,8 +29,14 @@ export class CustomEditor extends Editor {
 	public onCtrlT?: () => void;
 	public onCtrlG?: () => void;
 	public onCtrlZ?: () => void;
+	public onAltEnter?: () => void;
 
 	handleInput(data: string): void {
+		// Intercept Alt+Enter for follow-up messages
+		if (isAltEnter(data) && this.onAltEnter) {
+			this.onAltEnter();
+			return;
+		}
 		// Intercept Ctrl+G for external editor
 		if (isCtrlG(data) && this.onCtrlG) {
 			this.onCtrlG();

packages/coding-agent/src/modes/interactive/components/queue-mode-selector.ts

@@ -1,56 +0,0 @@
-import { Container, type SelectItem, SelectList } from "@mariozechner/pi-tui";
-import { getSelectListTheme } from "../theme/theme.js";
-import { DynamicBorder } from "./dynamic-border.js";
-
-/**
- * Component that renders a queue mode selector with borders
- */
-export class QueueModeSelectorComponent extends Container {
-	private selectList: SelectList;
-
-	constructor(
-		currentMode: "all" | "one-at-a-time",
-		onSelect: (mode: "all" | "one-at-a-time") => void,
-		onCancel: () => void,
-	) {
-		super();
-
-		const queueModes: SelectItem[] = [
-			{
-				value: "one-at-a-time",
-				label: "one-at-a-time",
-				description: "Process queued messages one by one (recommended)",
-			},
-			{ value: "all", label: "all", description: "Process all queued messages at once" },
-		];
-
-		// Add top border
-		this.addChild(new DynamicBorder());
-
-		// Create selector
-		this.selectList = new SelectList(queueModes, 2, getSelectListTheme());
-
-		// Preselect current mode
-		const currentIndex = queueModes.findIndex((item) => item.value === currentMode);
-		if (currentIndex !== -1) {
-			this.selectList.setSelectedIndex(currentIndex);
-		}
-
-		this.selectList.onSelect = (item) => {
-			onSelect(item.value as "all" | "one-at-a-time");
-		};
-
-		this.selectList.onCancel = () => {
-			onCancel();
-		};
-
-		this.addChild(this.selectList);
-
-		// Add bottom border
-		this.addChild(new DynamicBorder());
-	}
-
-	getSelectList(): SelectList {
-		return this.selectList;
-	}
-}

packages/coding-agent/src/modes/interactive/components/settings-selector.ts

@@ -24,7 +24,8 @@ const THINKING_DESCRIPTIONS: Record<ThinkingLevel, string> = {
 export interface SettingsConfig {
 	autoCompact: boolean;
 	showImages: boolean;
-	queueMode: "all" | "one-at-a-time";
+	steeringMode: "all" | "one-at-a-time";
+	followUpMode: "all" | "one-at-a-time";
 	thinkingLevel: ThinkingLevel;
 	availableThinkingLevels: ThinkingLevel[];
 	currentTheme: string;
@@ -36,7 +37,8 @@ export interface SettingsConfig {
 export interface SettingsCallbacks {
 	onAutoCompactChange: (enabled: boolean) => void;
 	onShowImagesChange: (enabled: boolean) => void;
-	onQueueModeChange: (mode: "all" | "one-at-a-time") => void;
+	onSteeringModeChange: (mode: "all" | "one-at-a-time") => void;
+	onFollowUpModeChange: (mode: "all" | "one-at-a-time") => void;
 	onThinkingLevelChange: (level: ThinkingLevel) => void;
 	onThemeChange: (theme: string) => void;
 	onThemePreview?: (theme: string) => void;
@@ -127,10 +129,17 @@ export class SettingsSelectorComponent extends Container {
 				values: ["true", "false"],
 			},
 			{
-				id: "queue-mode",
-				label: "Queue mode",
-				description: "How to process queued messages while agent is working",
-				currentValue: config.queueMode,
+				id: "steering-mode",
+				label: "Steering mode",
+				description: "How to deliver steering messages (Enter while streaming)",
+				currentValue: config.steeringMode,
+				values: ["one-at-a-time", "all"],
+			},
+			{
+				id: "follow-up-mode",
+				label: "Follow-up mode",
+				description: "How to deliver follow-up messages (queued until agent finishes)",
+				currentValue: config.followUpMode,
 				values: ["one-at-a-time", "all"],
 			},
 			{
@@ -227,8 +236,11 @@ export class SettingsSelectorComponent extends Container {
 					case "show-images":
 						callbacks.onShowImagesChange(newValue === "true");
 						break;
-					case "queue-mode":
-						callbacks.onQueueModeChange(newValue as "all" | "one-at-a-time");
+					case "steering-mode":
+						callbacks.onSteeringModeChange(newValue as "all" | "one-at-a-time");
+						break;
+					case "follow-up-mode":
+						callbacks.onFollowUpModeChange(newValue as "all" | "one-at-a-time");
 						break;
 					case "hide-thinking":
 						callbacks.onHideThinkingBlockChange(newValue === "true");

packages/coding-agent/src/modes/interactive/interactive-mode.ts

@@ -262,6 +262,9 @@ export class InteractiveMode {
 			theme.fg("dim", "!") +
 			theme.fg("muted", " to run bash") +
 			"\n" +
+			theme.fg("dim", "alt+enter") +
+			theme.fg("muted", " to queue follow-up") +
+			"\n" +
 			theme.fg("dim", "drop files") +
 			theme.fg("muted", " to attach");
 		const header = new Text(`${logo}\n${instructions}`, 1, 0);
@@ -776,6 +779,7 @@ export class InteractiveMode {
 		this.editor.onCtrlO = () => this.toggleToolOutputExpansion();
 		this.editor.onCtrlT = () => this.toggleThinkingBlockVisibility();
 		this.editor.onCtrlG = () => this.openExternalEditor();
+		this.editor.onAltEnter = () => this.handleAltEnter();
 
 		this.editor.onChange = (text: string) => {
 			const wasBashMode = this.isBashMode;
@@ -920,9 +924,9 @@ export class InteractiveMode {
 				}
 			}
 
-			// Queue regular messages if agent is streaming
+			// Queue steering message if agent is streaming (interrupts current work)
 			if (this.session.isStreaming) {
-				await this.session.queueMessage(text);
+				await this.session.steer(text);
 				this.updatePendingMessagesDisplay();
 				this.editor.addToHistory(text);
 				this.editor.setText("");
@@ -1447,6 +1451,24 @@ export class InteractiveMode {
 		process.kill(0, "SIGTSTP");
 	}
 
+	private async handleAltEnter(): Promise<void> {
+		const text = this.editor.getText().trim();
+		if (!text) return;
+
+		// Alt+Enter queues a follow-up message (waits until agent finishes)
+		if (this.session.isStreaming) {
+			await this.session.followUp(text);
+			this.updatePendingMessagesDisplay();
+			this.editor.addToHistory(text);
+			this.editor.setText("");
+			this.ui.requestRender();
+		}
+		// If not streaming, Alt+Enter acts like regular Enter (trigger onSubmit)
+		else if (this.editor.onSubmit) {
+			this.editor.onSubmit(text);
+		}
+	}
+
 	private updateEditorBorderColor(): void {
 		if (this.isBashMode) {
 			this.editor.borderColor = theme.getBashModeBorderColor();
@@ -1651,7 +1673,8 @@ export class InteractiveMode {
 				{
 					autoCompact: this.session.autoCompactionEnabled,
 					showImages: this.settingsManager.getShowImages(),
-					queueMode: this.session.queueMode,
+					steeringMode: this.session.steeringMode,
+					followUpMode: this.session.followUpMode,
 					thinkingLevel: this.session.thinkingLevel,
 					availableThinkingLevels: this.session.getAvailableThinkingLevels(),
 					currentTheme: this.settingsManager.getTheme() || "dark",
@@ -1672,8 +1695,11 @@ export class InteractiveMode {
 							}
 						}
 					},
-					onQueueModeChange: (mode) => {
-						this.session.setQueueMode(mode);
+					onSteeringModeChange: (mode) => {
+						this.session.setSteeringMode(mode);
+					},
+					onFollowUpModeChange: (mode) => {
+						this.session.setFollowUpMode(mode);
 					},
 					onThinkingLevelChange: (level) => {
 						this.session.setThinkingLevel(level);