feat(terminal) refactoring and stability improvements (#98)

* feat(terminal): replace xterm with ghostty-web

Replace xterm.js terminal with ghostty-web implementation
Add terminal serialization support for state restoration
Apply custom patches to ghostty-web for enhancements

* feat(terminal): add bun-pty backend support

Switch terminal to ghostty-web with bun-pty backend for better performance
Auto-detect and prefer Bun runtime when available for terminal sessions
Update terminal viewport write queue handling for improved reliability

* fix(terminal): prevent unnecessary resize events

Only report terminal resize when dimensions actually change
Simplify chunk processing state tracking
Disable terminal transparency for consistent rendering

* feat(terminal): increase scrollback and buffer limits

Increase terminal scrollback buffer from 10k to 50k lines
Increase terminal buffer limit from 256k to 1M bytes
Add rate limiting and improve output handling for terminal streams

packages/web/bin/cli.js

@@ -11,6 +11,35 @@ const __dirname = path.dirname(__filename);
 const DEFAULT_PORT = 3000;
 const PACKAGE_JSON = JSON.parse(fs.readFileSync(path.join(__dirname, '..', 'package.json'), 'utf8'));
 
+function getBunBinary() {
+  if (typeof process.env.BUN_BINARY === 'string' && process.env.BUN_BINARY.trim().length > 0) {
+    return process.env.BUN_BINARY.trim();
+  }
+  if (typeof process.env.BUN_INSTALL === 'string' && process.env.BUN_INSTALL.trim().length > 0) {
+    return path.join(process.env.BUN_INSTALL.trim(), 'bin', 'bun');
+  }
+  return 'bun';
+}
+
+const BUN_BIN = getBunBinary();
+
+function isBunRuntime() {
+  return typeof globalThis.Bun !== 'undefined';
+}
+
+function isBunInstalled() {
+  try {
+    const result = spawnSync(BUN_BIN, ['--version'], { stdio: 'ignore', env: process.env });
+    return result.status === 0;
+  } catch {
+    return false;
+  }
+}
+
+function getPreferredServerRuntime() {
+  return isBunInstalled() ? 'bun' : 'node';
+}
+
 function generateRandomPassword(length = 16) {
   const charset = 'ABCDEFGHJKLMNPQRSTUVWXYZabcdefghjkmnpqrstuvwxyz23456789';
   let password = '';
@@ -384,9 +413,12 @@ const commands = {
       serverArgs.push('--try-cf-tunnel');
     }
 
+    const preferredRuntime = getPreferredServerRuntime();
+    const runtimeBin = preferredRuntime === 'bun' ? BUN_BIN : process.execPath;
+
     if (options.daemon) {
 
-      const child = spawn(process.execPath, serverArgs, {
+      const child = spawn(runtimeBin, serverArgs, {
         detached: true,
         stdio: 'ignore',
         env: {
@@ -430,8 +462,29 @@ const commands = {
 
       writeInstanceOptions(instanceFilePath, { ...options, uiPassword: effectiveUiPassword });
 
+      // Prefer bun when installed (much faster PTY). If CLI is running under Node,
+      // run the server in a child process so Node doesn't have to load bun-pty.
+      if (preferredRuntime === 'bun' && !isBunRuntime()) {
+        const child = spawn(runtimeBin, serverArgs, {
+          stdio: 'inherit',
+          env: {
+            ...process.env,
+            OPENCHAMBER_PORT: options.port.toString(),
+            OPENCODE_BINARY: opencodeBinary,
+            ...(typeof effectiveUiPassword === 'string' ? { OPENCHAMBER_UI_PASSWORD: effectiveUiPassword } : {}),
+            OPENCHAMBER_TRY_CF_TUNNEL: options.tryCfTunnel ? 'true' : 'false',
+          },
+        });
+
+        child.on('exit', (code) => {
+          process.exit(typeof code === 'number' ? code : 1);
+        });
+
+        return;
+      }
+
       const { startWebUiServer } = await import(serverPath);
-      const server = await startWebUiServer({
+      await startWebUiServer({
         port: options.port,
         attachSignals: true,
         exitOnShutdown: true,