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/Views/ClipboardKeyboardViews.swift

@@ -243,9 +243,7 @@ struct ClipboardHistoryPanelView: View {
                 }
 
                 if history.entries.isEmpty {
-                    ExtL10n.text("keyboard.clipboard.panel.empty")
-                        .font(.system(size: 14))
-                        .foregroundStyle(palette.textSecondary)
+                    emptyState
                         .frame(maxWidth: .infinity, maxHeight: .infinity)
                 } else {
                     ScrollView {
@@ -277,6 +275,26 @@ struct ClipboardHistoryPanelView: View {
         .animation(.easeOut(duration: 0.16), value: showClearConfirmation)
     }
 
+    /// Icon + title + one-line hint, so an empty panel explains what fills it.
+    private var emptyState: some View {
+        VStack(spacing: 6) {
+            Image(systemName: "doc.on.clipboard")
+                .font(.system(size: 22, weight: .regular))
+                .foregroundStyle(palette.textTertiary)
+                .padding(.bottom, 4)
+                .accessibilityHidden(true)
+            ExtL10n.text("keyboard.clipboard.panel.empty")
+                .font(.system(size: 14, weight: .semibold))
+                .foregroundStyle(palette.textSecondary)
+            ExtL10n.text("keyboard.clipboard.panel.emptyHint")
+                .font(TypeStyle.caption.weight(.regular))
+                .foregroundStyle(palette.textTertiary)
+                .multilineTextAlignment(.center)
+        }
+        .padding(.horizontal, 24)
+        .accessibilityElement(children: .combine)
+    }
+
     private var clearConfirmationOverlay: some View {
         VStack(spacing: 12) {
             Image(systemName: "trash")