Allow dragging the macOS player controls bar to reposition it

The glass controls capsule can now be dragged anywhere over the video.
Position is stored as a fraction of the container size so it survives
window resizes and aspect-ratio driven sheet resizes, persists across
sessions via SettingsManager, and snaps back magnetically when dropped
near the default bottom-center spot. Travel is clamped so the capsule
stays inside the player and never overlaps the top button row. A
mouseDownCanMoveWindow=false backing view keeps the window's
movable-by-background behavior from swallowing the drag.

Yattee/Core/Settings/SettingsKey.swift

@@ -47,6 +47,8 @@ enum SettingsKey: String, CaseIterable {
     // Platform-specific
     case macPlayerSeparateWindow
     case macPlayerFloating
+    case macControlsBarOffsetX // Normalized X offset of macOS control bar from default position
+    case macControlsBarOffsetY // Normalized Y offset of macOS control bar from default position
     case playerSheetAutoResize
     case listStyle
 
@@ -140,6 +142,7 @@ enum SettingsKey: String, CaseIterable {
         switch self {
         case .preferredQuality, .cellularQuality, .allowSoftwareDecodedFormats,
              .macPlayerSeparateWindow, .macPlayerFloating, .listStyle,
+             .macControlsBarOffsetX, .macControlsBarOffsetY,
              // Home layout — different UI paradigms per platform
              .homeShortcutOrder, .homeShortcutVisibility, .homeShortcutLayout, .homeShortcutCardStyle,
              .homeShortcutCardColor, .homeShortcutColorfulPalette, .homeShortcutCustomPaletteColors,

Yattee/Core/Settings/SettingsManager+Player.swift

@@ -95,6 +95,34 @@ extension SettingsManager {
         }
     }
 
+    /// Normalized X offset of the macOS floating control bar from its default
+    /// bottom-center position, stored as a fraction of the player container width.
+    /// 0 = default docked position.
+    var macControlsBarOffsetX: Double {
+        get {
+            if let cached = _macControlsBarOffsetX { return cached }
+            return double(for: .macControlsBarOffsetX)
+        }
+        set {
+            _macControlsBarOffsetX = newValue
+            set(newValue, for: .macControlsBarOffsetX)
+        }
+    }
+
+    /// Normalized Y offset of the macOS floating control bar from its default
+    /// bottom-center position, stored as a fraction of the player container height.
+    /// 0 = default docked position.
+    var macControlsBarOffsetY: Double {
+        get {
+            if let cached = _macControlsBarOffsetY { return cached }
+            return double(for: .macControlsBarOffsetY)
+        }
+        set {
+            _macControlsBarOffsetY = newValue
+            set(newValue, for: .macControlsBarOffsetY)
+        }
+    }
+
     /// Whether the player sheet automatically resizes to match video aspect ratio.
     /// When enabled, the sheet window will resize when video loads or changes.
     /// Default is true.

Yattee/Core/SettingsManager.swift

@@ -74,6 +74,8 @@ final class SettingsManager {
     #if os(macOS)
     var _macPlayerSeparateWindow: Bool?
     var _macPlayerFloating: Bool?
+    var _macControlsBarOffsetX: Double?
+    var _macControlsBarOffsetY: Double?
     var _playerSheetAutoResize: Bool?
     #endif
 
@@ -460,6 +462,8 @@ final class SettingsManager {
         #if os(macOS)
         _macPlayerSeparateWindow = nil
         _macPlayerFloating = nil
+        _macControlsBarOffsetX = nil
+        _macControlsBarOffsetY = nil
         _playerSheetAutoResize = nil
         #endif
         // miniPlayerShowVideo and miniPlayerVideoTapAction moved to preset