**State** (`src/store/`): Redux Toolkit with two slices — `auth` (current user) and `firearms` (paginated firearm list). State is persisted to `localStorage` or `sessionStorage` based on the `VITE_REDUX_STORAGE` env var. Use typed hooks from `src/hooks/store.ts` (`useAppDispatch`, `useAppSelector`).
**API layer** (`src/api/`): Axios instance (`src/shared/web-client/`) with base URL from `VITE_API_BASE_URL`, 10s timeout, and credentials. API modules: `FirearmApi`, `ModificationApi`, `TagApi`, `AuthApi`.
**Pages**:
-`FirearmsPage` — paginated card grid with type filter, create/edit modals (admin-only), delete with popconfirm
-`ModCodesPage` — paginated list with tag multi-select and firearmId query param filter, create/edit modals with nested accessory/tuning form lists
-`LoginPage` — simple username/password form, dispatches `setCurrentUser` on success
**Shared form components**: `FirearmForm` and `ModificationForm` are reused by both create and edit modals. `ModificationForm` fetches all firearms for its weapon selector and supports a `lockFirearmId` prop that disables the selector (used when navigating from a specific firearm).
**Type system** (`src/types/`): `Firearm` with weapon stats, `Modification` with nested `Accessory[]` → `Tuning[]`, `Page<T>` for paginated API responses, `User` for auth.
**Vite config**: Alias `@` → `./src`. Plugins: React, Tailwind CSS 4, port checker. Build uses rolldown with manual chunk splitting for React, Redux, Ant Design, React Router, and rc-* packages.
**Styling**: Tailwind CSS 4 with CSS layers (`theme, base, antd, components, utilities`). Responsive grid for mod code cards (1→2→3→4 columns). Prettier: 100 print width, no semicolons, double quotes, trailing commas ES5.
## Environment variables
```
VITE_API_BASE_URL=/api # Backend API base URL
VITE_REDUX_STORAGE=local # "local" or "session" for Redux persistence
