Fix Windows browse daemon cold start

browse/src/cli.ts

@@ -239,7 +239,17 @@ async function startServer(extraEnv?: Record<string, string>): Promise<ServerSta
       `spawn(process.execPath,[${JSON.stringify(NODE_SERVER_SCRIPT)}],` +
       `{detached:true,stdio:['ignore','ignore','ignore'],env:Object.assign({},process.env,` +
       `${extraEnvStr})}).unref()`;
-    spawnSync('node', ['-e', launcherCode], { stdio: 'ignore' });
+    const launcher = Bun.spawnSync(['node', '-e', launcherCode], {
+      stdout: 'pipe',
+      stderr: 'pipe',
+      timeout: 5000,
+    });
+    const launcherExit = (launcher as any).exitCode ?? (launcher as any).status ?? 0;
+    if (launcherExit !== 0) {
+      const stderr = launcher.stderr?.toString().trim();
+      const stdout = launcher.stdout?.toString().trim();
+      throw new Error(`Windows launcher failed${stderr || stdout ? `:\n${stderr || stdout}` : ''}`);
+    }
   } else {
     // macOS/Linux: Bun.spawn().unref() only removes the child from Bun's event
     // loop — it does NOT call setsid(), so the spawned server stays in the

browse/src/server.ts

@@ -129,7 +129,7 @@ let activeShutdown: ((code?: number) => Promise<void>) | null = null;
 // silently weakened by misconfiguration.
 function sanitizeAuthToken(raw: string | undefined): string | null {
   if (!raw) return null;
-  const stripped = raw.replace(/[\s ​-‍]/g, '');
+  const stripped = raw.replace(/[\s\u00a0\u200b-\u200d\ufeff]/g, '');
   if (stripped.length < 16) return null;
   return stripped;
 }

browse/src/terminal-agent-control.ts

@@ -19,6 +19,54 @@ import * as path from 'path';
 import { safeUnlink, safeKill, isProcessAlive } from './error-handling';
 import { writeSecureFile, mkdirSecure } from './file-permissions';
 
+export interface BunSpawnCommand {
+  command: string;
+  argsPrefix: string[];
+}
+
+function envPath(env: Record<string, string | undefined>): string {
+  return env.PATH || env.Path || env.path || '';
+}
+
+/**
+ * Resolve a Bun executable suitable for a detached child spawn.
+ *
+ * On Windows, npm installs expose `bun` as a POSIX shell shim plus `bun.cmd`.
+ * Node/Bun process spawning does not reliably execute those shims directly,
+ * so prefer the real `node_modules/bun/bin/bun.exe` beside them.
+ */
+export function resolveBunSpawnCommand(
+  env: Record<string, string | undefined> = process.env,
+  platform: NodeJS.Platform = process.platform,
+  execPath: string = process.execPath,
+): BunSpawnCommand | null {
+  if (platform !== 'win32') return { command: 'bun', argsPrefix: [] };
+
+  if (execPath && path.basename(execPath).toLowerCase() === 'bun.exe' && fs.existsSync(execPath)) {
+    return { command: execPath, argsPrefix: [] };
+  }
+
+  const dirs = envPath(env).split(path.delimiter).filter(Boolean);
+  for (const dir of dirs) {
+    const candidates = [
+      path.join(dir, 'bun.exe'),
+      path.join(dir, 'node_modules', 'bun', 'bin', 'bun.exe'),
+    ];
+    for (const candidate of candidates) {
+      if (fs.existsSync(candidate)) return { command: candidate, argsPrefix: [] };
+    }
+
+    for (const shim of ['bun.cmd', 'bun.bat']) {
+      const shimPath = path.join(dir, shim);
+      if (fs.existsSync(shimPath)) {
+        return { command: 'cmd.exe', argsPrefix: ['/d', '/s', '/c', `"${shimPath}"`] };
+      }
+    }
+  }
+
+  return null;
+}
+
 /**
  * Locate the terminal-agent script on disk. In dev (cli.ts running via
  * `bun run`), it lives next to this file in browse/src. In a compiled
@@ -68,16 +116,24 @@ export function spawnTerminalAgent(opts: {
   }
   const script = opts.scriptPath || resolveTerminalAgentScript();
   if (!script || !fs.existsSync(script)) return null;
-  const proc = (Bun as any).spawn(['bun', 'run', script], {
-    cwd: opts.cwd || process.cwd(),
-    env: {
-      ...process.env,
-      BROWSE_STATE_FILE: opts.stateFile,
-      BROWSE_SERVER_PORT: String(opts.serverPort),
-      ...(opts.extraEnv || {}),
-    },
-    stdio: ['ignore', 'ignore', 'ignore'],
-  });
+  const bun = resolveBunSpawnCommand();
+  if (!bun) return null;
+  let proc: any;
+  try {
+    proc = (Bun as any).spawn([bun.command, ...bun.argsPrefix, 'run', script], {
+      cwd: opts.cwd || process.cwd(),
+      env: {
+        ...process.env,
+        BROWSE_STATE_FILE: opts.stateFile,
+        BROWSE_SERVER_PORT: String(opts.serverPort),
+        ...(opts.extraEnv || {}),
+      },
+      stdio: ['ignore', 'ignore', 'ignore'],
+    });
+  } catch (err: any) {
+    if (err?.code === 'ENOENT' || err?.code === 'EACCES') return null;
+    throw err;
+  }
   proc.unref?.();
   return proc.pid ?? null;
 }

browse/test/config.test.ts

@@ -1,5 +1,6 @@
 import { describe, test, expect } from 'bun:test';
 import { resolveConfig, ensureStateDir, readVersionHash, getGitRoot, getRemoteSlug, resolveGstackHome, resolveChromiumProfile, cleanSingletonLocks } from '../src/config';
+import { resolveBunSpawnCommand } from '../src/terminal-agent-control';
 import * as fs from 'fs';
 import * as path from 'path';
 import * as os from 'os';
@@ -342,6 +343,42 @@ describe('cli command dispatch', () => {
     expect(cliSource).toContain('Starting server in headed mode');
     expect(cliSource).toContain('Starting server with proxy');
   });
+
+  test('Windows launcher uses Bun.spawnSync for compiled CLI compatibility', () => {
+    expect(cliSource).toContain("Bun.spawnSync(['node', '-e', launcherCode]");
+    expect(cliSource).not.toContain("spawnSync('node', ['-e', launcherCode]");
+  });
+});
+
+describe('server source portability', () => {
+  const serverSource = fs.readFileSync(path.resolve(__dirname, '../src/server.ts'), 'utf-8');
+
+  test('auth-token whitespace regex uses ASCII escapes for Node bundle safety', () => {
+    expect(serverSource).toContain('raw.replace(/[\\s\\u00a0\\u200b-\\u200d\\ufeff]/g');
+    expect(serverSource).not.toContain('raw.replace(/[\\s ');
+  });
+});
+
+describe('terminal agent spawn command', () => {
+  test('Windows npm bun shim resolves to real bun.exe', () => {
+    const tmpDir = fs.mkdtempSync(path.join(os.tmpdir(), 'browse-bun-shim-'));
+    const bunExe = path.join(tmpDir, 'node_modules', 'bun', 'bin', 'bun.exe');
+    fs.mkdirSync(path.dirname(bunExe), { recursive: true });
+    fs.writeFileSync(path.join(tmpDir, 'bun.cmd'), '@echo off\n');
+    fs.writeFileSync(bunExe, '');
+
+    try {
+      const result = resolveBunSpawnCommand({ PATH: tmpDir }, 'win32', 'C:\\Windows\\System32\\node.exe');
+      expect(result).toEqual({ command: bunExe, argsPrefix: [] });
+    } finally {
+      fs.rmSync(tmpDir, { recursive: true, force: true });
+    }
+  });
+
+  test('Windows missing bun is non-fatal for terminal-agent spawn', () => {
+    const result = resolveBunSpawnCommand({ PATH: '' }, 'win32', 'C:\\Windows\\System32\\node.exe');
+    expect(result).toBeNull();
+  });
 });
 
 describe('write command dispatch', () => {