// Add or update this route in your node.cjs file
app.post('/api/signup', async (req, res) => {
    try {
        const { username, password } = req.body;
        
        // This triggers your AuthService which calls the BIP39 C++ logic
        const result = await authService.signup(username, password);
        
        // Return success with address and mnemonic so verify.html can move forward
        res.json({ 
            success: true, 
            address: result.address, 
            mnemonic: result.mnemonic 
        });
    } catch (e) { 
        res.status(400).json({ success: false, error: e.message }); 
    }
});