feat(keyboard): harden polish/clipboard guards and ship 1.6.6 (build 59)

Keep marketing version at 1.6.6 and bump build to 59. Strengthen never-answer
polish safeguards, clipboard reply-intent continuity, voice undo UX, device
UITests harness, eval fixtures, and What's New assets.

OSGKeyboardShared/DesignSystem/RecordButtonGesturePolicy.swift

@@ -0,0 +1,60 @@
+// RecordButtonGesturePolicy.swift
+// OSGKeyboard · Shared
+//
+// Pure tap / hold routing for the mic button. Kept out of the view so the
+// "one press produces at most one action" invariant is unit-testable: the
+// clipboard long-press flips the phase while the finger is still down, and
+// regressions there let a single press both open and close a round.
+
+import Foundation
+
+public enum RecordButtonGestureAction: Equatable, Sendable {
+    case none
+    /// Start dictation, cancel a preparing clipboard intent, or stop recording —
+    /// all of which the coordinator resolves from its own phase.
+    case toggle
+    case beginClipboardCommand
+}
+
+public enum RecordButtonGesturePolicy {
+    /// Action for a press released before the hold threshold.
+    public static func tapAction(
+        phase: RecordButton.Phase,
+        isEnabled: Bool
+    ) -> RecordButtonGestureAction {
+        switch phase {
+        case .idleUnavailable:
+            return .toggle
+        case .idleReady, .error, .preparing, .recording:
+            return isEnabled ? .toggle : .none
+        case .processing:
+            return .none
+        }
+    }
+
+    /// Action for a press held past the threshold. A `.none` result means the
+    /// hold did not consume the press, so its release still counts as a tap and
+    /// no gesture becomes a dead key.
+    public static func holdAction(
+        phase: RecordButton.Phase,
+        isEnabled: Bool,
+        supportsClipboardLongPress: Bool
+    ) -> RecordButtonGestureAction {
+        switch phase {
+        case .idleReady, .idleUnavailable, .error:
+            guard supportsClipboardLongPress else { return .none }
+            guard isEnabled || phase == .idleUnavailable else { return .none }
+            return .beginClipboardCommand
+        case .recording:
+            return isEnabled ? .toggle : .none
+        case .preparing, .processing:
+            return .none
+        }
+    }
+
+    /// A hold that produced an action owns the press; its release must be
+    /// swallowed rather than replayed as a tap.
+    public static func consumesPress(_ action: RecordButtonGestureAction) -> Bool {
+        action != .none
+    }
+}