refactor: Streamline project configuration and styling

This commit simplifies the Vite configuration by removing unnecessary options like `base`, `sourcemap`, and custom `rollupOptions`. It also removes the explicit server port definition, allowing Vite to manage it.

Additionally, minor styling adjustments are made to the scrollbar in `index.html` and default values for select inputs in `AccountsPayableView` are updated for clarity. The `engines` property was removed from `package.json` as it's not strictly necessary for typical development workflows.

components/AccountsPayableView.tsx

@@ -282,7 +282,7 @@ export const AccountsPayableView: React.FC<AccountsPayableViewProps> = ({ expens
                 <div>
                   <label className="block text-sm font-bold text-slate-800 mb-1">Categoria</label>
                   <CustomSelect 
-                    value={newExpense.category ?? 'Operacional'}
+                    value={newExpense.category || 'Operacional'}
                     onChange={(val) => setNewExpense({...newExpense, category: val})}
                     options={[
                         { value: 'Operacional', label: 'Operacional' },
@@ -296,7 +296,7 @@ export const AccountsPayableView: React.FC<AccountsPayableViewProps> = ({ expens
                 <div>
                   <label className="block text-sm font-bold text-slate-800 mb-1">Tipo</label>
                   <CustomSelect 
-                    value={newExpense.type ?? 'fixed'}
+                    value={newExpense.type || 'fixed'}
                     onChange={(val) => setNewExpense({...newExpense, type: val})}
                     options={[
                         { value: 'fixed', label: 'Fixa' },