perf(desktop): reduce terminal memory footprint

apps/desktop/src/main/lib/terminal-host/headless-emulator.ts

@@ -9,6 +9,7 @@
 
 import { SerializeAddon } from "@xterm/addon-serialize";
 import { Terminal } from "@xterm/headless";
+import { DEFAULT_TERMINAL_SCROLLBACK } from "shared/constants";
 import {
 	DEFAULT_MODES,
 	type TerminalModes,
@@ -75,7 +76,11 @@ export class HeadlessEmulator {
 	private static readonly MAX_ESCAPE_BUFFER_SIZE = 1024;
 
 	constructor(options: HeadlessEmulatorOptions = {}) {
-		const { cols = 80, rows = 24, scrollback = 10000 } = options;
+		const {
+			cols = 80,
+			rows = 24,
+			scrollback = DEFAULT_TERMINAL_SCROLLBACK,
+		} = options;
 
 		this.terminal = new Terminal({
 			cols,
@@ -224,7 +229,8 @@ export class HeadlessEmulator {
 	 */
 	getSnapshot(): TerminalSnapshot {
 		const snapshotAnsi = this.serializeAddon.serialize({
-			scrollback: this.terminal.options.scrollback ?? 10000,
+			scrollback:
+				this.terminal.options.scrollback ?? DEFAULT_TERMINAL_SCROLLBACK,
 		});
 
 		const rehydrateSequences = this.generateRehydrateSequences();
@@ -323,6 +329,9 @@ export class HeadlessEmulator {
 	dispose(): void {
 		if (this.disposed) return;
 		this.disposed = true;
+		// Clear scrollback buffer before disposing to release memory immediately
+		// rather than waiting for GC to collect the terminal instance.
+		this.terminal.clear();
 		this.terminal.dispose();
 	}
 

apps/desktop/src/main/lib/terminal/session.ts

@@ -2,6 +2,7 @@ import os from "node:os";
 import { SerializeAddon } from "@xterm/addon-serialize";
 import { Terminal as HeadlessTerminal } from "@xterm/headless";
 import * as pty from "node-pty";
+import { DEFAULT_TERMINAL_SCROLLBACK } from "shared/constants";
 import { getShellArgs } from "../agent-setup";
 import { DataBatcher } from "../data-batcher";
 import {
@@ -14,7 +15,6 @@ import type { InternalCreateSessionParams, TerminalSession } from "./types";
 
 const DEFAULT_COLS = 80;
 const DEFAULT_ROWS = 24;
-const DEFAULT_SCROLLBACK = 10000;
 /** Max time to wait for agent hooks before running initial commands */
 const AGENT_HOOKS_TIMEOUT_MS = 2000;
 const DEBUG_TERMINAL = process.env.SUPERSET_TERMINAL_DEBUG === "1";
@@ -24,7 +24,7 @@ export function createHeadlessTerminal(params: {
 	rows: number;
 	scrollback?: number;
 }): { headless: HeadlessTerminal; serializer: SerializeAddon } {
-	const { cols, rows, scrollback = DEFAULT_SCROLLBACK } = params;
+	const { cols, rows, scrollback = DEFAULT_TERMINAL_SCROLLBACK } = params;
 
 	const headless = new HeadlessTerminal({
 		cols,

apps/desktop/src/main/terminal-host/session.ts

@@ -11,6 +11,7 @@
 import { type ChildProcess, spawn } from "node:child_process";
 import type { Socket } from "node:net";
 import * as path from "node:path";
+import { DEFAULT_TERMINAL_SCROLLBACK } from "shared/constants";
 import { buildSafeEnv } from "../lib/terminal/env";
 import { HeadlessEmulator } from "../lib/terminal-host/headless-emulator";
 import type {
@@ -136,7 +137,7 @@ export class Session {
 		this.emulator = new HeadlessEmulator({
 			cols: options.cols,
 			rows: options.rows,
-			scrollback: options.scrollbackLines ?? 10000,
+			scrollback: options.scrollbackLines ?? DEFAULT_TERMINAL_SCROLLBACK,
 		});
 
 		// Set initial CWD

apps/desktop/src/renderer/screens/main/components/WorkspaceView/ContentView/TabsContent/Terminal/config.ts

@@ -1,4 +1,5 @@
 import type { ITerminalOptions } from "@xterm/xterm";
+import { DEFAULT_TERMINAL_SCROLLBACK } from "shared/constants";
 
 // Use user's theme
 export const TERMINAL_THEME: ITerminalOptions["theme"] = undefined;
@@ -39,7 +40,7 @@ export const TERMINAL_OPTIONS: ITerminalOptions = {
 	fontFamily: DEFAULT_TERMINAL_FONT_FAMILY,
 	theme: TERMINAL_THEME,
 	allowProposedApi: true,
-	scrollback: 10000,
+	scrollback: DEFAULT_TERMINAL_SCROLLBACK,
 	// Allow Option+key to type special characters on international keyboards (e.g., Option+2 = @)
 	macOptionIsMeta: false,
 	cursorStyle: "block",

apps/desktop/src/shared/constants.ts

@@ -42,6 +42,7 @@ export const DEFAULT_FILE_OPEN_MODE = "split-pane" as const;
 export const DEFAULT_AUTO_APPLY_DEFAULT_PRESET = true;
 export const DEFAULT_SHOW_PRESETS_BAR = false;
 export const DEFAULT_TELEMETRY_ENABLED = true;
+export const DEFAULT_TERMINAL_SCROLLBACK = 5000;
 
 // External links (documentation, help resources, etc.)
 export const EXTERNAL_LINKS = {