fix: add windowsHide to prevent console window flashing on Windows (#401)

Every child_process.spawn() call was creating a visible console window
on Windows, causing disruptive flashing during MCP tool use. Added
windowsHide: true to spawn options in 5 files:
- src/terminal-manager.ts (2 spawn calls)
- src/search-manager.ts
- src/tools/improved-process-tools.ts
- src/utils/open-browser.ts
- src/remote-device/desktop-commander-integration.ts

windowsHide is silently ignored on macOS/Linux (UV_PROCESS_WINDOWS_HIDE
is a no-op on those platforms), so this is safe cross-platform.

Co-authored-by: Claude Sonnet 4.6 <noreply@anthropic.com>

Author: phuryn

src/remote-device/desktop-commander-integration.ts

@@ -94,7 +94,7 @@ export class DesktopCommanderIntegration {
                 // We can't run it directly as it's an stdio MCP server that waits for input
                 const whichCommand = process.platform === 'win32' ? 'where' : 'which';
                 console.debug('[DEBUG] Using platform command:', whichCommand, 'on platform:', process.platform);
-                const check = spawn(whichCommand, [commandName]);
+                const check = spawn(whichCommand, [commandName], { windowsHide: true });  // Prevent visible console windows on Windows
                 check.on('error', (err) => {
                     console.debug('[DEBUG] Spawn error for', whichCommand, ':', err.message);
                     reject(err);

src/search-manager.ts

@@ -81,7 +81,7 @@ export interface SearchSessionOptions {
     }
 
     // Start ripgrep process
-    const rgProcess = spawn(rgPath, args);
+    const rgProcess = spawn(rgPath, args, { windowsHide: true });  // Prevent visible console windows on Windows
 
     if (!rgProcess.pid) {
       throw new Error('Failed to start ripgrep process');

src/terminal-manager.ts

@@ -160,9 +160,10 @@ export class TerminalManager {
         env: {
           ...process.env,
           TERM: 'xterm-256color'  // Better terminal compatibility
-        }
+        },
+        windowsHide: true  // Prevent visible console windows on Windows
       };
-      
+
       // Add shell option if needed (for unknown shells)
       if (spawnConfig.useShellOption) {
         spawnOptions.shell = spawnConfig.useShellOption;
@@ -179,7 +180,8 @@ export class TerminalManager {
         env: {
           ...process.env,
           TERM: 'xterm-256color'
-        }
+        },
+        windowsHide: true  // Prevent visible console windows on Windows
       };
     }
 

src/tools/improved-process-tools.ts

@@ -33,7 +33,8 @@ async function executeNodeCode(code: string, timeout_ms: number = 30000): Promis
     const result = await new Promise<{ stdout: string; stderr: string; exitCode: number }>((resolve) => {
       const proc = spawn(process.execPath, [tempFile], {
         cwd: mcpRoot,
-        timeout: timeout_ms
+        timeout: timeout_ms,
+        windowsHide: true  // Prevent visible console windows on Windows
       });
 
       let stdout = '';

src/utils/open-browser.ts

@@ -26,7 +26,7 @@ export async function openBrowser(url: string): Promise<void> {
         break;
       case 'win32':
         // Windows 'start' is a shell builtin, use spawn with shell but pass URL as separate arg
-        spawn('cmd', ['/c', 'start', '', url], { shell: false }).on('close', (code) => {
+        spawn('cmd', ['/c', 'start', '', url], { shell: false, windowsHide: true }).on('close', (code) => {
           code === 0 ? resolve() : reject(new Error(`Exit code ${code}`));
         });
         break;