chore: scaffold Voice iOS app (Phase 0)

XcodeGen project, SwiftUI iOS 17 target dev.shane.voice, SPM
livekit-client-swift 2.16.0, mic usage + ATS LAN exception in
Info.plist, placeholder conversation screen and Settings with
server URL field.

Voice.xcodeproj/project.xcworkspace/contents.xcworkspacedata

@@ -0,0 +1,7 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<Workspace
+   version = "1.0">
+   <FileRef
+      location = "self:">
+   </FileRef>
+</Workspace>