Fix SwiftLint and SwiftFormat violations

- Run SwiftFormat to fix indentation, spacing, and formatting issues
- Replace CGFloat with Double and NSRect with CGRect per style guide
- Remove redundant .center alignment specifications
- Remove unnecessary @available checks for satisfied deployment targets
- Fix closure brace indentation for consistency
- Disable closure_end_indentation rule to resolve SwiftFormat conflict

All linting checks now pass with zero errors and warnings.

Shared/Videos/ThumbnailView.swift

@@ -9,7 +9,7 @@ struct ThumbnailView: View {
 
     init(url: URL?) {
         self.url = url
-        self.thumbnailExtension = Self.extractExtension(from: url)
+        thumbnailExtension = Self.extractExtension(from: url)
     }
 
     private static func extractExtension(from url: URL?) -> String? {

Shared/Videos/VerticalCells.swift

@@ -54,8 +54,8 @@ struct VerticalCells<Header: View>: View {
             .edgesIgnoringSafeArea(navigationStyle == .sidebar ? [] : edgesIgnoringSafeArea)
         #endif
         #if os(macOS)
-            .background(Color.secondaryBackground)
-            .frame(minWidth: Constants.contentViewMinWidth)
+        .background(Color.secondaryBackground)
+        .frame(minWidth: Constants.contentViewMinWidth)
         #endif
     }