Add Kevin Viers Venmo link to About, build 20

Co-Authored-By: Claude Sonnet 5.5 <noreply@anthropic.com>

ios/Stemify/UI/Screens/SettingsScreens.swift

@@ -266,6 +266,8 @@ private struct Maintainer: Identifiable {
     let color: UInt32
     let site: (title: String, icon: String, value: String, url: String)
     let coffee: String?
+    var tipTitle = "Buy Me a Coffee"
+    var tipIcon = "cup.and.saucer.fill"
     var id: String { name }
 }
 
@@ -275,7 +277,7 @@ private let maintainers = [
                coffee: "https://buymeacoffee.com/cdnutter"),
     Maintainer(name: "Kevin Viers", role: "stemd and the Android app", avatar: "AvatarKevin", color: Stems.color("drums"),
                site: ("GitHub", "chevron.left.forwardslash.chevron.right", "kevinViers", "https://github.com/kevinViers/"),
-               coffee: nil),
+               coffee: "https://venmo.com/code?user_id=2910252785729536546&created=1792897467", tipTitle: "Venmo", tipIcon: "dollarsign.circle.fill"),
 ]
 
 /// A maintainer's picture in a ring of their stem colour, their name and what they look after.
@@ -330,7 +332,7 @@ struct AboutScreen: View {
                     .themedRow()
                     if let coffee = m.coffee {
                         Link(destination: URL(string: coffee)!) {
-                            ValueCell(title: "Buy Me a Coffee", value: nil, icon: "cup.and.saucer.fill", iconBg: 0xFF9500)
+                            ValueCell(title: m.tipTitle, value: nil, icon: m.tipIcon, iconBg: 0xFF9500)
                         }
                         .themedRow()
                     } else {
@@ -347,7 +349,7 @@ struct AboutScreen: View {
             }
             Section {
             } footer: {
-                Footer(text: "Stemify is free. A coffee goes straight to the person you pick.")
+                Footer(text: "Stemify is free. A tip goes straight to the person you pick.")
                     .frame(maxWidth: .infinity)
                     .multilineTextAlignment(.center)
             }