feat: keyboard bottom-row layout, handedness preference, and screen wake lock

Rework the action cluster to a mic-above-bottom-row layout, add left/right
handedness setting that swaps delete and return, and keep the screen awake
during Flow recording sessions.

OSGKeyboardShared/Services/AppGroupStore.swift

@@ -46,6 +46,7 @@ public struct AppGroupStore: @unchecked Sendable {
         // computed shim for source compatibility.
         static let translationTargetLocaleId = "config.translationTargetLocaleId"
         static let polishScenarioId = "config.polishScenarioId"
+        static let handednessPreference = "config.handednessPreference"
     }
 
     // MARK: - Reads
@@ -133,6 +134,11 @@ public struct AppGroupStore: @unchecked Sendable {
         return PolishScenarioCatalog.resolve(stored ?? PolishScenarioCatalog.defaultId).id
     }
 
+    /// Bottom-row key order on the keyboard extension.
+    public var handednessPreference: HandednessPreference {
+        HandednessPreference.fromStored(defaults.string(forKey: Key.handednessPreference))
+    }
+
     // MARK: - Writes
 
     public func setModeId(_ id: String) {
@@ -184,6 +190,11 @@ public struct AppGroupStore: @unchecked Sendable {
         AppGroupConfigDarwin.postConfigChanged()
     }
 
+    public func setHandednessPreference(_ preference: HandednessPreference) {
+        defaults.set(preference.rawValue, forKey: Key.handednessPreference)
+        AppGroupConfigDarwin.postConfigChanged()
+    }
+
     /// Whether ASR output should be sent through the cloud LLM step.
     /// Cloud engine: always. Local engine: only when cloud polish is
     /// enabled (translation is a sub-option of that step).