Move DriverBridge, DriverError, AppAudioMonitor, TrackedApp, and
HelperProtocol from AppFaders to AppFadersCore shared library. Update
Package.swift to add AppFadersCore dependency and update test imports.

Replace CLI entry point with proper macOS menu bar application architecture:
- AppFadersApp: @main entry using NSApplication.run() pattern for proper
  delegate lifecycle management
- AppDelegate: NSApplicationDelegate with .accessory activation policy,
  AudioOrchestrator integration, and graceful termination handling
- MenuBarController: NSStatusItem stub with SF Symbol icon (slider.vertical.3)

This establishes the foundation for the NSPanel-based volume control UI.

Add left-click panel toggle and right-click context menu to the menu bar
status item. The context menu provides "Open" and "Quit" options. Panel
show/hide methods are placeholders that log actions until the panel UI
is implemented in subsequent tasks.

- Configure NSPanel as floating, non-activating panel with borderless style
- Add PlaceholderPanelView with basic styling and dark/light mode support
- Wire panel show/hide to MenuBarController toggle methods

Position panel below menu bar status item with screen bounds checking.
Add event monitors to dismiss panel on click outside or Escape key press.

- Custom SwiftUI slider matching Pencil design specs.
- Large (300px) and small (200px) variants with DragGesture control.
- Asset catalog provides light/dark mode colors for all UI components.

- SF Symbol icons: speaker.wave.2.fill / speaker.slash.fill
- asset catalog colors for automatic light/dark mode adaptation.

- Panel chrome with title, settings icon placeholder, version label, and quit button.
- Uses asset catalog colors for light/dark mode.

- header row with "MASTER OUTPUT" label and percentage display.
- slider row with large VolumeSlider and MuteButton.

- added volume control row with icon, name/percentage display, small VolumeSlider, and MuteButton.
- added memberwise init for AppVolumeState to support previews.

- combines HeaderView, dividers, MasterVolumeView, app rows, and FooterView.
- added panel styling
- uses @bindable for AppState with async volume bindings.

- asset catalog wasn't working and I don't have patience to keep debugging right now.

…ix panel visibility

Asset catalogs aren't compiled by SPM's .process() directive, causing
runtime "No color named" errors. Replace with AppColors enum using
programmatic light/dark mode support.

- Remove Colors.xcassets and Resources directory
- Update all views to use AppColors instead of Color(bundle:)
- Set hidesOnDeactivate=false on NSPanel (required for menu bar apps)
- Wire PanelView to MenuBarController with AppState
- Remove unused PlaceholderPanelView

- added filtering for AppAudioMonitor with .regular to make list sensible.

- moved list population from async start() to init() so list pops faster.