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.

OSGKeyboardShared/Models/LLMProvider.swift

@@ -108,4 +108,11 @@ public struct LLMProvider: Identifiable, Codable, Hashable, Sendable {
     public static var userSelectablePresets: [LLMProvider] {
         presets.filter(\.isUserSelectable)
     }
+
+    /// Cloud ASR presets (excludes providers without a cloud transcription API).
+    public static var asrSelectablePresets: [LLMProvider] {
+        userSelectablePresets.filter {
+            CloudASRModelCatalog.strategy(for: $0.id) != .localFallback
+        }
+    }
 }