fix(kiro): add --no-incognito option for normal browser auth

Kiro OAuth always opens in incognito browser mode, which doesn't save
login credentials. Users need to re-enter email each authentication.

Changes:
- Add noIncognito option to OAuthOptions interface
- Add kiro_no_incognito config option to CLIProxyConfig
- Pass --no-incognito flag to CLIProxyAPI binary when enabled
- Support both CLI flag (--no-incognito) and config.yaml setting

Usage:
- CLI: ccs kiro --auth --no-incognito
- Config: cliproxy.kiro_no_incognito: true in config.yaml

src/cliproxy/auth/oauth-handler.ts

@@ -126,7 +126,7 @@ export async function triggerOAuth(
   options: OAuthOptions = {}
 ): Promise<AccountInfo | null> {
   const oauthConfig = getOAuthConfig(provider);
-  const { verbose = false, add = false, nickname, fromUI = false } = options;
+  const { verbose = false, add = false, nickname, fromUI = false, noIncognito = false } = options;
   const callbackPort = OAUTH_PORTS[provider];
   const isCLI = !fromUI;
   const headless = options.headless ?? isHeadlessEnvironment();
@@ -175,6 +175,10 @@ export async function triggerOAuth(
   if (headless) {
     args.push('--no-browser');
   }
+  // Kiro-specific: --no-incognito to use normal browser (saves login credentials)
+  if (provider === 'kiro' && noIncognito) {
+    args.push('--no-incognito');
+  }
 
   // Show step based on flow type
   if (isDeviceCodeFlow) {