feat(account): add managed credits and cloud gateway

Introduce optional Apple account-backed credits with scoped gateway access while preserving local and BYOK paths. Refresh assistant behavior, tests, privacy disclosures, docs, and the website for the 2.0 experience.

OSGKeyboardExt/Typing/CandidateExpandGridView.swift

@@ -4,9 +4,9 @@
 // UIKit grid for the expanded Chinese candidate panel. UILabel cells +
 // UICollectionView recycling stay far cheaper than hundreds of SwiftUI Buttons.
 
+import OSGKeyboardShared
 import SwiftUI
 import UIKit
-import OSGKeyboardShared
 
 struct CandidateExpandGridView: UIViewRepresentable {
     var candidates: [TypingCandidate]

OSGKeyboardExt/Typing/KeyboardSurfaceRoot.swift

@@ -3,8 +3,8 @@
 //
 // Switches between voice and typing surfaces driven by KeyboardState.surface.
 
-import SwiftUI
 import OSGKeyboardShared
+import SwiftUI
 
 struct KeyboardSurfaceRoot: View {
     @Environment(\.colorScheme) private var colorScheme

OSGKeyboardExt/Typing/TypingKeyTouchPad.swift

@@ -6,9 +6,9 @@
 // overlapping fingers commit in press order, delete repeats on down,
 // Shift holds while that finger owns it.
 
+import OSGKeyboardShared
 import SwiftUI
 import UIKit
-import OSGKeyboardShared
 
 struct TypingKeyTouchPad: UIViewRepresentable {
     var layout: TypingKeyLayout

OSGKeyboardExt/Typing/TypingRootView.swift

@@ -4,8 +4,8 @@
 // Typing surface: candidate bar + QWERTY / 123 / symbols.
 // Top-leading control returns to the voice surface.
 
-import SwiftUI
 import OSGKeyboardShared
+import SwiftUI
 
 enum TypingLayoutMetrics {
     // Size decisions live in `TypingSurfaceMetrics` (Shared) so the UIKit