feat: add domain models and repositories for user, spool presets, and filaments

- Introduced SpoolPreset and User domain models with necessary DTOs and utility functions.
- Created AuthRepository, FilamentRepository, and SpoolPresetRepository interfaces for authentication and data management.
- Implemented UI components for filament display, including ColorSwatch, FilamentCard, and StockBar.
- Developed layout components such as Header and Screen for consistent app structure.
- Added reusable UI components like Badge, Button, Card, and Input for better user interaction.
- Established global constants and theme settings for consistent styling across the application.
- Implemented utility functions for filament calculations and formatting.
- Created Zustand stores for managing authentication, filament, and preset states.
- Configured TypeScript settings for improved development experience.

mobile/app/(app)/(tabs)/add.tsx

@@ -0,0 +1,17 @@
+import React from 'react';
+import { useRouter } from 'expo-router';
+import { Screen } from '@presentation/components/layout/Screen';
+
+/**
+ * Tab "add" — apenas redireciona para o formulário de novo filamento.
+ * O FAB central da tab bar chama esta rota.
+ */
+export default function AddTab(): React.ReactElement {
+  const router = useRouter();
+
+  React.useEffect(() => {
+    router.replace('/(app)/inventory/new');
+  }, [router]);
+
+  return <Screen />;
+}