feat: add native plan decisions to the TUI

packages/coding-agent/src/modes/interactive/components/footer.ts

@@ -98,7 +98,8 @@ export class FooterComponent implements Component {
 		const modelName = state.model?.id || "no-model";
 		const thinkingLevel = state.thinkingLevel || "off";
 		const windowDisplay = `${formatTokens(contextWindow)} window`;
-		let statsLine = `${modelName} ${thinkingLevel} • ${contextPercentStr} • ${windowDisplay}`;
+		const planStatus = this.session.collaborationMode === "plan" ? "[plan] " : "";
+		let statsLine = `${planStatus}${modelName} ${thinkingLevel} • ${contextPercentStr} • ${windowDisplay}`;
 
 		if (visibleWidth(statsLine) > width) {
 			statsLine = truncateToWidth(statsLine, width, "...");

packages/coding-agent/src/modes/interactive/components/plan-message.ts

@@ -0,0 +1,46 @@
+import {
+	Box,
+	Container,
+	Markdown,
+	type MarkdownTheme,
+	Spacer,
+	stripTerminalSequences,
+	Text,
+} from "@earendil-works/diffex-tui";
+import type { MarkdownTransformer } from "../../../core/extensions/types.ts";
+import type { PlanArtifact } from "../../../core/plan-mode.ts";
+import { getMarkdownTheme, theme } from "../theme/theme.ts";
+import { createMarkdownTransform } from "./markdown-transform.ts";
+
+/** Renders a submitted plan as a first-class transcript artifact. */
+export class PlanMessageComponent extends Container {
+	constructor(
+		plan: PlanArtifact,
+		markdownTheme: MarkdownTheme = getMarkdownTheme(),
+		outputPad = 1,
+		markdownTransformers: readonly MarkdownTransformer[] = [],
+	) {
+		super();
+		this.addChild(new Spacer(1));
+
+		const box = new Box(outputPad, 1, (content) => theme.bg("customMessageBg", content));
+		const title = stripTerminalSequences(plan.title).replace(/\s+/gu, " ").trim() || "Untitled plan";
+		box.addChild(new Text(theme.bold(theme.fg("customMessageLabel", `Plan: ${title}`)), 0, 0));
+		box.addChild(new Spacer(1));
+		box.addChild(
+			new Markdown(
+				plan.markdown,
+				0,
+				0,
+				markdownTheme,
+				{ color: (content) => theme.fg("customMessageText", content) },
+				{
+					preserveOrderedListMarkers: true,
+					preserveBackslashEscapes: true,
+					transform: createMarkdownTransform("assistant", false, markdownTransformers),
+				},
+			),
+		);
+		this.addChild(box);
+	}
+}

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

@@ -362,6 +362,8 @@ class TreeList implements Component {
 				entry.type === "custom" ||
 				entry.type === "model_change" ||
 				entry.type === "thinking_level_change" ||
+				entry.type === "collaboration_mode_change" ||
+				entry.type === "plan_resolution" ||
 				entry.type === "session_info";
 
 			switch (this.filterMode) {
@@ -605,6 +607,15 @@ class TreeList implements Component {
 			case "thinking_level_change":
 				parts.push("thinking", entry.thinkingLevel);
 				break;
+			case "collaboration_mode_change":
+				parts.push("collaboration mode", entry.mode);
+				break;
+			case "plan":
+				parts.push("plan", entry.plan.title, entry.plan.markdown);
+				break;
+			case "plan_resolution":
+				parts.push("plan resolution", entry.resolution, entry.planId);
+				break;
 			case "custom":
 				parts.push("custom", entry.customType);
 				break;
@@ -835,6 +846,15 @@ class TreeList implements Component {
 			case "thinking_level_change":
 				result = theme.fg("dim", `[thinking: ${entry.thinkingLevel}]`);
 				break;
+			case "collaboration_mode_change":
+				result = theme.fg("dim", `[collaboration mode: ${entry.mode}]`);
+				break;
+			case "plan":
+				result = theme.fg("accent", "[plan]: ") + normalize(entry.plan.title);
+				break;
+			case "plan_resolution":
+				result = theme.fg("dim", `[plan resolution: ${entry.resolution}]`);
+				break;
 			case "custom":
 				result = theme.fg("dim", `[custom: ${entry.customType}]`);
 				break;
@@ -919,6 +939,15 @@ class TreeList implements Component {
 			case "branch_summary":
 				text = entry.summary;
 				break;
+			case "collaboration_mode_change":
+				text = `Collaboration mode: ${entry.mode}`;
+				break;
+			case "plan":
+				text = `${entry.plan.title}\n\n${entry.plan.markdown}`;
+				break;
+			case "plan_resolution":
+				text = `Plan ${entry.planId}: ${entry.resolution}`;
+				break;
 		}
 
 		return text?.trim() ? text : undefined;