Store macOS account passwords in Keychain

docs/porting-to-dotnet.md

@@ -855,6 +855,8 @@ AppKit application that consumes `VoiceCat.Core` directly. It implements guest a
 connection, validated saved server profiles whose JSON never contains passwords,
 interactive TOFU approval, protected-channel password prompts, channel browsing, roster/chat,
 voice subscription, native accessibility labels and default-device microphone/playback.
+Account passwords can be stored in macOS Keychain after successful authentication and are
+removed when the user disables remembering or deletes the profile.
 Core Audio capture is resampled
 and converted through `AVAudioConverter` before entering the managed audio engine. Stereo
 playback uses `AVAudioSourceNode` and the shared bounded PCM ring; its render callback does
@@ -862,8 +864,8 @@ not allocate, lock or block. Voice stream lifetime follows subscription, disconn
 channel changes. Current Apple API calls compile warning-free against Microsoft's
 26.4.10259 macOS reference assembly, and a macOS CI job builds the native codec/DSP shim and
 Apple solution. A real macOS device run and listen test remain required. The existing Swift
-app remains the release client until optional Keychain credentials, selectable devices, the
-rest of the moderation/settings surface, ScreenCaptureKit, VoiceOver
+app remains the release client until selectable devices, the rest of the moderation/settings
+surface, ScreenCaptureKit, VoiceOver
 validation, signing and notarization are complete.
 
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