# Feature: Core UI and Camera Feed (PyObjC)

## Status: COMPLETE

## Description
Create the main application window using PyObjC (AppKit) and display a live camera feed. This ensures a native macOS look and feel.

## Requirements

1.  **App & Window Setup (AppKit)**:
    - Initialize `NSApplication`.
    - Create a main `NSWindow` titled "ItemSense".
    - Size: 800x600 (resizable).
    - Window should center on screen.

2.  **UI Layout**:
    - Use `NSStackView` (vertical) or manual constraints to layout:
        - Top: Video Feed (`NSImageView`).
        - Bottom: "Capture" button (`NSButton`).

3.  **Camera Feed**:
    - Use `opencv-python` to capture frames from webcam (index 0).
    - Convert frames (`cv2` BGR -> RGB) to `NSImage/CGImage`.
    - Update the `NSImageView` at ~30 FPS using a timer (`NSTimer` or equivalent app loop integration).

4.  **Capture Button**:
    - Standard macOS Push Button.
    - Label: "Capture".
    - Action: Print "Capture clicked" to console.

5.  **Lifecycle**:
    - Ensure `Cmd+Q` works.
    - Ensure closing the window terminates the app (or at least the `applicationShouldTerminateAfterLastWindowClosed:` delegate method returns True).

## Acceptance Criteria

- [ ] App launches with a native macOS window "ItemSense".
- [ ] Live camera feed is visible in the view.
- [ ] "Capture" button is visible at the bottom.
- [ ] Clicking "Capture" prints to console.
- [ ] App exits cleanly on window close or Cmd+Q.