feat(tips): use the minimized send button only in tip chats

Flipcash/Core/Screens/Conversation/ChatScreenRepresentable.swift

@@ -39,6 +39,8 @@ struct ChatScreenRepresentable: UIViewControllerRepresentable {
     let onSendCash: () -> Void
     let conversationController: ConversationController
     let barModel: ConversationBarModel
+    /// Whether this is a tip DM — the send button then stays minimized.
+    let isTipDm: Bool
 
     func makeUIViewController(context: Context) -> ChatScreenViewController {
         let barHost = UIHostingController(rootView: bar(coordinator: context.coordinator))
@@ -96,7 +98,8 @@ struct ChatScreenRepresentable: UIViewControllerRepresentable {
                 conversationID: conversationID,
                 symbol: symbol,
                 onSendCash: onSendCash,
-                model: barModel
+                model: barModel,
+                isTipDm: isTipDm
             )
             .environment(conversationController)
             .modifier(MeasuredBarHeight { coordinator.screen?.setBarHeight($0) })

Flipcash/Core/Screens/Conversation/ConversationBottomBar.swift

@@ -46,6 +46,9 @@ struct ConversationBottomBar: View {
     let symbol: String
     let onSendCash: () -> Void
     let model: ConversationBarModel
+    /// Tip chats always show the compact symbol-only send button; ordinary
+    /// chats expand to "Send €" at rest and collapse only while composing.
+    var isTipDm: Bool = false
 
     var body: some View {
         let content = HStack(alignment: .bottom, spacing: 10) {
@@ -54,6 +57,7 @@ struct ConversationBottomBar: View {
                     symbol: symbol,
                     composing: model.isComposing,
                     standalone: !chatExists,
+                    alwaysMinimized: isTipDm,
                     action: onSendCash
                 )
             }
@@ -170,8 +174,9 @@ private struct BarGradientBackground: ViewModifier {
 }
 
 /// The Send Cash button, rendered as a white "Send €" pill at rest and a
-/// compact glass "€" square while composing. Alone in the bar it takes the
-/// standard filled-button size; beside the composer it's field-sized.
+/// compact glass "€" square while composing (or always, in a tip chat). Alone
+/// in the bar it takes the standard filled-button size; beside the composer
+/// it's field-sized.
 // One persistent view: the morph animates its properties (prefix text, fill,
 // width, color) in lockstep — splitting the two states into separate views
 // would crossfade instead of morphing.
@@ -182,8 +187,15 @@ struct SendCashMorphButton: View {
     /// Whether the button is the bar's only control (no chat yet): it spans
     /// the bar at the standard filled-button size instead of field-sized.
     let standalone: Bool
+    /// Forces the compact symbol-only presentation regardless of composing.
+    /// Tip chats always show it minimized; ordinary chats expand at rest.
+    var alwaysMinimized: Bool = false
     let action: () -> Void
 
+    /// The compact glass "€" presentation: while composing, or always in a tip
+    /// chat. The whole morph (label, fill, width, color) keys off this.
+    private var minimized: Bool { composing || alwaysMinimized }
+
     private var height: CGFloat {
         standalone ? Metrics.buttonHeight : BarMetrics.contentHeight
     }
@@ -195,24 +207,24 @@ struct SendCashMorphButton: View {
     var body: some View {
         Button(action: action) {
             HStack(spacing: 4) {
-                if !composing {
+                if !minimized {
                     Text("Send")
                         .font(.appTextMedium)
                         .transition(.opacity)
                 }
                 Text(symbol)
                     // Same persistent Text — .interpolate animates the glyph
                     // between sizes; swapping views would crossfade.
-                    .font(composing ? .appTextXL : .appTextMedium)
+                    .font(minimized ? .appTextXL : .appTextMedium)
                     .contentTransition(.interpolate)
             }
-            .foregroundStyle(composing ? Color.textMain : Color.textAction)
+            .foregroundStyle(minimized ? Color.textMain : Color.textAction)
             // The label must never reflow to "Se…" mid-morph; overflow is
             // clipped by the shape instead.
             .fixedSize()
-            .padding(.horizontal, composing ? 0 : 20)
+            .padding(.horizontal, minimized ? 0 : 20)
             .frame(minWidth: BarMetrics.contentHeight)
-            .frame(maxWidth: standalone && !composing ? .infinity : nil)
+            .frame(maxWidth: standalone && !minimized ? .infinity : nil)
             .frame(height: height)
         }
         .buttonStyle(.plain)
@@ -221,7 +233,7 @@ struct SendCashMorphButton: View {
         .background {
             RoundedRectangle(cornerRadius: cornerRadius)
                 .fill(Color.action)
-                .opacity(composing ? 0 : 1)
+                .opacity(minimized ? 0 : 1)
         }
         .glassBackground(cornerRadius: cornerRadius)
         .clipShape(RoundedRectangle(cornerRadius: cornerRadius))

Flipcash/Core/Screens/Conversation/ConversationScreen.swift

@@ -167,7 +167,8 @@ struct ConversationScreen: View {
             symbol: ratesController.balanceCurrency.compactSymbol,
             onSendCash: sendCash,
             conversationController: conversationController,
-            barModel: barModel
+            barModel: barModel,
+            isTipDm: tipCounterpart != nil
         )
         .ignoresSafeArea(.keyboard)
         // Extend the transcript under the navigation bar so content scrolls beneath it — that's