fix: reduce Windows console popups in web backend

Prefer graceful process termination before taskkill fallback
Force ConPTY for Windows terminal sessions to avoid console flashes
Keep git and server process operations running without visible command windows

packages/web/server/lib/opencode/lifecycle.js

@@ -124,6 +124,15 @@ export const createOpenCodeLifecycleRuntime = (deps) => {
     }
 
     if (process.platform === 'win32') {
+      try {
+        child.kill();
+      } catch {
+      }
+
+      if (await waitForChildProcessClose(child, 800)) {
+        return;
+      }
+
       try {
         spawnSync('taskkill', ['/pid', String(pid), '/t'], {
           stdio: 'ignore',

packages/web/server/lib/terminal/runtime.js

@@ -130,7 +130,7 @@ export function createTerminalRuntime({
     let lastError = null;
     for (const shell of shellCandidates) {
       try {
-        const ptyProcess = pty.spawn(shell, [], {
+        const ptyOptions = {
           name: 'xterm-256color',
           cols: cols || 80,
           rows: rows || 24,
@@ -140,7 +140,13 @@ export function createTerminalRuntime({
             TERM: 'xterm-256color',
             COLORTERM: 'truecolor',
           },
-        });
+        };
+
+        if (process.platform === 'win32') {
+          ptyOptions.useConpty = true;
+        }
+
+        const ptyProcess = pty.spawn(shell, [], ptyOptions);
 
         return { ptyProcess, shell };
       } catch (error) {