Reuse native macOS Git credentials

docs/git-synchronization.md

@@ -32,7 +32,8 @@ repository mutation instead of treating its configuration as malformed.
 ## HTTPS transport
 
 HTTPS credentials are requested with the configured server ID and application
-ID and remain outside Git configuration.
+ID and remain outside Git configuration. macOS resolves them solely through
+the standard Internet-password credential for the same HTTPS endpoint.
 
 Fetch uses the embedded Rust smart-HTTP client with an explicit credential
 callback, so Git's credential cascade is never entered. Push implements the

docs/secure-secret-storage.md

@@ -29,7 +29,10 @@ The platform-selection code is isolated in
 
 - macOS uses legacy Keychain for command-line-compatible device-unlocked
   credentials and Protected Data for `RequireUserPresence`; iOS uses Protected
-  Data. User cancellation is mapped from the native Security Framework status.
+  Data. macOS HTTPS synchronization uses only the unique standard
+  Internet-password credential matching the remote endpoint; it does not use
+  an IronStorage-specific Git credential locator. User cancellation is mapped
+  from the native Security Framework status.
 - Windows uses Credential Manager. Store operations are serialized because the
   upstream adapter documents unreliable same-entry sequencing across threads.
 - Linux uses Secret Service through zbus with the Rust cryptography feature. It