feat(coding-agent/modes): added debug transcript export command to dump visible TUI conversation

- Added transcript export option to debug menu that writes visible TUI conversation to a temporary text file.
- Implemented handleDebugTranscriptCommand in CommandController to render chat messages, strip ANSI codes, and write to temp directory.
- Updated InteractiveModeContext interface and InteractiveMode to expose the new debug transcript command handler.

packages/coding-agent/src/debug/index.ts

@@ -27,6 +27,11 @@ const DEBUG_MENU_ITEMS: SelectItem[] = [
 	{ value: "memory", label: "Report: memory issue", description: "Heap snapshot + bundle" },
 	{ value: "logs", label: "View: recent logs", description: "Show last 50 log entries" },
 	{ value: "system", label: "View: system info", description: "Show environment details" },
+	{
+		value: "transcript",
+		label: "Export: TUI transcript",
+		description: "Write visible TUI conversation to a temp txt",
+	},
 	{ value: "clear-cache", label: "Clear: artifact cache", description: "Remove old session artifacts" },
 ];
 
@@ -95,6 +100,9 @@ export class DebugSelectorComponent extends Container {
 			case "system":
 				await this.#handleViewSystemInfo();
 				break;
+			case "transcript":
+				await this.#handleTranscriptExport();
+				break;
 			case "clear-cache":
 				await this.#handleClearCache();
 				break;
@@ -323,6 +331,9 @@ export class DebugSelectorComponent extends Container {
 		this.ctx.ui.requestRender();
 	}
 
+	async #handleTranscriptExport(): Promise<void> {
+		await this.ctx.handleDebugTranscriptCommand();
+	}
 	async #handleOpenArtifacts(): Promise<void> {
 		const sessionFile = this.ctx.sessionManager.getSessionFile();
 		if (!sessionFile) {

packages/coding-agent/src/modes/controllers/command-controller.ts

@@ -28,6 +28,7 @@ import type { AuthStorage } from "../../session/auth-storage";
 import { createCompactionSummaryMessage } from "../../session/messages";
 import { outputMeta } from "../../tools/output-meta";
 import { resolveToCwd } from "../../tools/path-utils";
+import { replaceTabs } from "../../tools/render-utils";
 import { getChangelogPath, parseChangelog } from "../../utils/changelog";
 import { openPath } from "../../utils/open";
 
@@ -70,6 +71,25 @@ export class CommandController {
 		}
 	}
 
+	async handleDebugTranscriptCommand(): Promise<void> {
+		try {
+			const width = Math.max(1, this.ctx.ui.terminal.columns);
+			const renderedLines = this.ctx.chatContainer.render(width).map(line => replaceTabs(Bun.stripANSI(line)));
+			const rendered = renderedLines.join("\n").trimEnd();
+			if (!rendered) {
+				this.ctx.showError("No messages to dump yet.");
+				return;
+			}
+			const tmpPath = path.join(os.tmpdir(), `${Snowflake.next()}-tmp.txt`);
+			await Bun.write(tmpPath, `${rendered}\n`);
+			this.ctx.showStatus(`Debug transcript written to:\n${tmpPath}`);
+		} catch (error: unknown) {
+			this.ctx.showError(
+				`Failed to write debug transcript: ${error instanceof Error ? error.message : "Unknown error"}`,
+			);
+		}
+	}
+
 	async handleShareCommand(): Promise<void> {
 		const tmpFile = path.join(os.tmpdir(), `${Snowflake.next()}.html`);
 		const cleanupTempFile = async () => {

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

@@ -947,6 +947,10 @@ export class InteractiveMode implements InteractiveModeContext {
 		return this.#commandController.handleDumpCommand();
 	}
 
+	handleDebugTranscriptCommand(): Promise<void> {
+		return this.#commandController.handleDebugTranscriptCommand();
+	}
+
 	handleShareCommand(): Promise<void> {
 		return this.#commandController.handleShareCommand();
 	}

packages/coding-agent/src/modes/types.ts

@@ -154,6 +154,7 @@ export interface InteractiveModeContext {
 	handleChangelogCommand(showFull?: boolean): Promise<void>;
 	handleHotkeysCommand(): void;
 	handleDumpCommand(): Promise<void>;
+	handleDebugTranscriptCommand(): Promise<void>;
 	handleClearCommand(): Promise<void>;
 	handleForkCommand(): Promise<void>;
 	handleBashCommand(command: string, excludeFromContext?: boolean): Promise<void>;

packages/coding-agent/src/slash-commands/builtin-registry.ts

@@ -394,7 +394,7 @@ const BUILTIN_SLASH_COMMAND_REGISTRY: ReadonlyArray<BuiltinSlashCommandSpec> = [
 	},
 	{
 		name: "debug",
-		description: "Write debug log (TUI state and messages)",
+		description: "Open debug tools selector",
 		handle: (_command, runtime) => {
 			runtime.ctx.showDebugSelector();
 			runtime.ctx.editor.setText("");