feat(profile): other-user profile with overflow menu and pinned chat action

Flipcash/Core/Controllers/ConversationController.swift

@@ -1691,6 +1691,12 @@ final class ConversationController {
         }
     }
 
+    /// The ID of the tip DM with `userID`, or nil when the chat hasn't started. The single "chat
+    /// started" rule: the visible DM. Hidden chats are excluded, and a block takes precedence anyway.
+    func tipDMID(withUserID userID: UserID) -> ConversationID? {
+        tipDM(withUserID: userID)?.id
+    }
+
     private func contactName(for conversationID: ConversationID) -> String? {
         guard let name = contactNaming.contactDisplayName(forDMChat: conversationID),
               !name.isEmpty else {

Flipcash/Core/Navigation/AppRouter.swift

@@ -267,6 +267,19 @@ final class AppRouter {
         return StackPosition(stack: stack, depth: max(self[stack].count - 1, 0))
     }
 
+    /// The topmost stack and how many destinations it holds — the position of the screen on top of it.
+    /// `nil` when there is no topmost stack.
+    func positionOfTopmost() -> StackPosition? {
+        guard let stack = topmostStack else { return nil }
+        return StackPosition(stack: stack, depth: self[stack].count)
+    }
+
+    /// Whether `position` is still the topmost stack's top, so nothing has been pushed over it and no
+    /// other tab or sheet is in front.
+    func isTopmost(_ position: StackPosition) -> Bool {
+        positionOfTopmost() == position
+    }
+
     /// Pops `position.stack` back down to `position.depth`, leaving whatever sat beneath intact.
     func popTo(_ position: StackPosition) {
         popLast(self[position.stack].count - position.depth, on: position.stack)

Flipcash/Core/Screens/Conversation/StartChattingSheet.swift

@@ -33,11 +33,15 @@ struct StartChattingSheet: View {
     /// opened for once the send lands and the floor no longer applies.
     let fee: FiatAmount
 
+    /// Called once the payment lands, before the sheet's success hold and dismissal.
+    var didSucceed: () -> Void = {}
+
     var body: some View {
         StartChattingSheetContent(
             sessionContainer: sessionContainer,
             target: target,
-            fee: fee
+            fee: fee,
+            onSuccess: didSucceed
         )
     }
 }
@@ -51,15 +55,18 @@ private struct StartChattingSheetContent: View {
     @State private var didSucceed: Bool = false
 
     private let fee: FiatAmount
+    private let onSuccess: () -> Void
 
     // MARK: - Init -
 
     init(
         sessionContainer: SessionContainer,
         target: SendTarget,
-        fee: FiatAmount
+        fee: FiatAmount,
+        onSuccess: @escaping () -> Void
     ) {
         self.fee = fee
+        self.onSuccess = onSuccess
         _viewModel = State(initialValue: SendAmountViewModel(
             sessionContainer: sessionContainer,
             target: target
@@ -108,6 +115,7 @@ private struct StartChattingSheetContent: View {
                     switch await viewModel.submit(entered: amount.value) {
                     case .success:
                         didSucceed = true
+                        onSuccess()
                     case .recipientNotFound:
                         dismiss()
                         throw StartChattingDismissed()