Add explicit sizing to sheets on macOS

Give player, download, source, and login sheets minimum frame dimensions on macOS so they open at a usable size instead of collapsing.

Yattee/Views/Settings/EditSourceView.swift

@@ -531,6 +531,9 @@ private struct EditFileSourceContent: View {
                     smbProtocolVersion = source.smbProtocolVersion ?? .auto
                 }
         }
+        #if os(macOS)
+        .frame(minWidth: 500, minHeight: 450)
+        #endif
         #endif
     }
 

Yattee/Views/Settings/InstanceLoginView.swift

@@ -43,6 +43,9 @@ struct InstanceLoginView: View {
                 }
                 .accessibilityIdentifier("instance.login.view")
         }
+        #if os(macOS)
+        .frame(minWidth: 450, minHeight: 350)
+        #endif
         #endif
     }
 

Yattee/Views/Settings/NetworkShareDiscoverySheet.swift

@@ -54,6 +54,9 @@ struct NetworkShareDiscoverySheet: View {
                     discoveryService?.stopDiscovery()
                 }
         }
+        #if os(macOS)
+        .frame(minWidth: 450, minHeight: 400)
+        #endif
     }
 
     @ViewBuilder