fix(cliproxy): inherit stdin for OAuth interactive prompts

Change stdio from 'ignore' to 'inherit' for stdin in auth subprocess,
allowing CLIProxy to receive user input for email/alias prompts during
Qwen and other OAuth flows.

Fixes #91

src/cliproxy/auth-handler.ts

@@ -553,7 +553,7 @@ export async function triggerOAuth(
   return new Promise<AccountInfo | null>((resolve) => {
     // Spawn CLIProxyAPI with auth flag (and --no-browser if headless)
     const authProcess = spawn(binaryPath, args, {
-      stdio: ['ignore', 'pipe', 'pipe'],
+      stdio: ['inherit', 'pipe', 'pipe'],
       env: {
         ...process.env,
         CLI_PROXY_AUTH_DIR: tokenDir,