Consider migration from findViewById to ViewBinding

[callebtc]

Description:
The app currently uses findViewById for view access, which is less performant and more error-prone than ViewBinding.

Current State:

• findViewById calls throughout activities
• Manual view casting and null checks
• Potential for runtime crashes if view IDs change

Benefits of ViewBinding:

1. Type Safety: Generated classes ensure correct view types
2. Null Safety: Only views that exist in layout are accessible
3. Performance: No findViewById lookups at runtime
4. IDE Support: Better autocomplete and refactoring

Fix Instructions:

1. Enable ViewBinding in build.gradle:

android {
    buildFeatures {
        viewBinding = true
    }
}

2. Update activities to use ViewBinding:

class ModernPOSActivity : AppCompatActivity() {
    private lateinit var binding: ActivityModernPosBinding
    
    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
        binding = ActivityModernPosBinding.inflate(layoutInflater)
        setContentView(binding.root)
        
        // Access views via binding
        binding.amountDisplay.text = "Amount"
        binding.submitButton.setOnClickListener { ... }
    }
}

Migration Strategy:

1. Start with new activities/fragments
2. Gradually migrate existing ones
3. Keep both approaches during transition

Priority: Medium - improves performance and safety