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.

OSGKeyboardMac/MacDictationResult.swift

@@ -0,0 +1,12 @@
+// MacDictationResult.swift
+// OSGKeyboard · Mac
+
+import Foundation
+
+struct MacDictationResult: Sendable, Equatable {
+    let text: String
+    /// Shown when DeepSeek / cloud polish failed but raw ASR was delivered.
+    let polishWarning: String?
+    /// Non-fatal per-chunk ASR issues from long utterance chunking.
+    let chunkWarning: String?
+}