feat: harden Flow cold-start/force-quit and polish macOS dictation UX

Fix cold-start overlay recursion that overflowed the main-thread stack when
recording began while the ready overlay was still up; also remove temporary
on-screen Flow DEBUG panels after the orange-mic investigation, and land the
macOS overlay/catalog/layout polish plus related Flow recovery hardening.

OSGKeyboardLiveActivity/en.lproj/Localizable.strings

@@ -0,0 +1,7 @@
+/* Live Activity captions. Keys are the English literals used in
+   FlowLiveActivityWidget — SwiftUI Text(_:) resolves string literals as
+   LocalizedStringKey against this table automatically. */
+"Voice session active" = "Voice session active";
+"Listening…" = "Listening…";
+"Transcribing…" = "Transcribing…";
+"Session disconnected · tap to reconnect" = "Session disconnected · tap to reconnect";