# Role

You are a Senior Flutter Developer working on "Colosseum's Choice".
The core battle and item system are working perfectly.
Your goal is to implement the **Inventory UI** and **Navigation System**.

# Requirements

1.  **Navigation (`BottomNavigationBar`):**

    - Create a main wrapper screen to switch between "Battle" and "Inventory".
    - **Critical:** Use `IndexedStack` to preserve the state of the `BattleScreen` (keep the fight running) while viewing the Inventory.

2.  **Inventory Screen:**

    - Display the Player's detailed Stats (Total ATK, Total HP, Armor, etc.).
    - List all collected/equipped items (`player.equipment`).
    - Show each item's name and bonus stats (e.g., "Rusty Sword (+2 ATK)").

3.  **Refactoring:**
    - Update `main.dart` to point to the new Main Wrapper Screen.

# Required Files

Please generate the code for the following files.

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## 1. `lib/screens/inventory_screen.dart` (New File)

**Description:**

- **Header:** Show Player Name, Stage, Total HP, Total ATK, Current Armor.
- **Body:** A `ListView` of `player.equipment`.
- **Item Tile:** `Card` or `ListTile` showing:
  - Leading: Icon (e.g., `Icons.shield` or `Icons.security`).
  - Title: Item Name.
  - Subtitle: Description & Stat Bonuses.
- **State:** Use `Consumer<BattleProvider>` to display live data.

## 2. `lib/screens/main_wrapper.dart` (New File)

**Description:**

- **Widget:** `StatefulWidget`.
- **State:** Holds `_currentIndex` (0 = Battle, 1 = Inventory).
- **Build:**
  - Return a `Scaffold`.
  - `body`: `IndexedStack` with children `[BattleScreen(), InventoryScreen()]`.
  - `bottomNavigationBar`: `BottomNavigationBar` with 2 items:
    - Battle (`Icons.sports_kabaddi` or `Icons.flash_on`).
    - Inventory (`Icons.backpack` or `Icons.inventory`).
  - **Theme:** Ensure the bottom bar matches the Dark Theme.

## 3. `lib/main.dart` (Update)

**Description:**

- Change `home` from `BattleScreen` to `MainWrapper`.

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# Output Format

Please provide the complete code for the 3 files above.