Remove unused components and models for improved maintainability

- Deleted redundant components (`AddActionButton`, `AlertBox`, `AlertStack`, `BackButton`, `CancelButton`, and `CollapsableArea`) and related files.
- Removed unused models (`Book`, `BookSerie`, `BookTables`, `Character`, and `Chapter`) to reduce codebase clutter.
- Updated project structure and references to reflect these removals.

components/form/NumberInput.tsx

@@ -42,13 +42,7 @@ export default function NumberInput(
             type="number"
             value={value ?? ''}
             onChange={handleChange}
-            className={`w-full bg-secondary/50 text-text-primary px-4 py-2.5 rounded-xl border border-secondary/50
-                focus:border-primary focus:ring-4 focus:ring-primary/20 focus:bg-secondary
-                hover:bg-secondary hover:border-secondary
-                placeholder:text-muted/60
-                outline-none transition-all duration-200
-                ${disabled ? 'opacity-50 cursor-not-allowed' : ''}
-                ${readOnly ? 'cursor-default' : ''}`}
+            className="input-base"
             placeholder={placeholder}
             readOnly={readOnly}
             disabled={disabled}