chore(release): bump version to 2.1.6 (build 131)

Version: CURRENT_PROJECT_VERSION 130 -> 131 (project.yml, AGENTS.md, READMEs,
docs/llms.txt).

fix(flow): host-app identification now compiles in every build configuration
(Debug, TestFlight, Release). The arbiter probe and HostAppIdentity were
DEBUG-only, so TestFlight/App Store builds never knew the host bundle id and
could not auto-return after a startflow handoff. Debug-only logging and the
Home test card are unchanged.

Also includes the pending work in the tree:
- Home: single account/setup card surface (HomeAccountSurfacePolicy/Views)
- Wide screens: voice key row and centred mic placement, iPhone Duo layout
- Keyboard: clipboard skill ranking and AI skill layout updates
- Debug: account session handoff to the Simulator (+ import script)
- Docs: portfolio assets, privacy policy URL, site/README refresh

OSGKeyboardExt/Typing/KeyboardSurfaceRoot.swift

@@ -38,9 +38,16 @@ struct KeyboardSurfaceRoot: View {
     static func height(
         for surface: KeyboardState.Surface,
         isIPad: Bool = false,
-        width: CGFloat = 0
+        width: CGFloat = 0,
+        isExpandedPhone: Bool = false,
+        isCompactHeightPhone: Bool = false
     ) -> CGFloat {
-        TypingSurfaceMetrics.contentHeight(isIPad: isIPad, width: width)
+        TypingSurfaceMetrics.contentHeight(
+            isIPad: isIPad,
+            width: width,
+            isExpandedPhone: isExpandedPhone,
+            isCompactHeightPhone: isCompactHeightPhone
+        )
     }
 
     var body: some View {