revert(username): keep UsernameProgressCard for possible reuse

It has no callers after the You tab redesign, but it may come back.

Author: bmc08gt

Flipcash/Core/Screens/Main/Username/UsernameProgressCard.swift

@@ -0,0 +1,112 @@
+//
+//  UsernameProgressCard.swift
+//  Flipcash
+//
+
+import SwiftUI
+import FlipcashUI
+
+/// The You-tab card offering a username, in the tip-card action group below
+/// Share/Download (Figma nodes 9536:4336 / 9537:1845). Superseded the
+/// settings-row entry point: `YouScreen` shows it only while
+/// `shouldPromptForUsername` holds, in place of the row it used to draw.
+///
+/// Takes plain values rather than reading `Session`/`UsernameGate` itself, so
+/// it can be previewed and tested without a signed-in account — the caller
+/// (`YouScreen`) is the one place that has both.
+struct UsernameProgressCard: View {
+
+    /// Which of the two states the card draws. The title never changes; the
+    /// state governs the bar's colour, the chevron, and where the tap lands.
+    enum State: Equatable {
+        /// Below the server's minimum (node 9536:4336): white bar, the
+        /// shortfall in place of a chevron. Tapping raises the balance gate.
+        case incomplete
+        /// At or above it (node 9537:1845): green bar, chevron. Tapping opens
+        /// the claim screen.
+        case complete
+    }
+
+    private static let title = "Get a custom @username"
+
+    let state: State
+    let subtitle: String
+    /// The shortfall, shown only in `.incomplete`. `nil` in `.complete`.
+    let trailing: String?
+    /// The balance's progress toward the minimum, `0...1`.
+    let fraction: Double
+    /// Runs on tap. Both states are tappable: the card is the entry point to
+    /// the flow either way, and below the minimum that means being told the
+    /// rule rather than being left with an inert bar.
+    let action: VoidAction
+
+    var body: some View {
+        Button(action: action) {
+            chrome
+        }
+        .buttonStyle(.plain)
+        .accessibilityLabel(Self.title)
+        // The shortfall reads as part of the hint rather than as a value: it
+        // is the same sentence the subtitle starts, not a separate reading.
+        .accessibilityHint(trailing.map { "\(subtitle). \($0)" } ?? subtitle)
+    }
+
+    private var chrome: some View {
+        VStack(alignment: .leading, spacing: 6) {
+            HStack(alignment: .firstTextBaseline, spacing: 8) {
+                Text(Self.title)
+                    .font(.default(size: 14, weight: .semibold))
+                    .foregroundStyle(Color.textMain)
+
+                if let trailing {
+                    Spacer(minLength: 8)
+                    Text(trailing)
+                        .font(.default(size: 14, weight: .semibold))
+                        .foregroundStyle(Color.textMain.opacity(0.5))
+                }
+
+                if state == .complete {
+                    Spacer(minLength: 8)
+                    Image.system(.chevronRight)
+                        .renderingMode(.template)
+                        .frame(width: 20, height: 20)
+                        .foregroundStyle(Color.textMain)
+                }
+            }
+
+            Text(subtitle)
+                .font(.default(size: 12, weight: .medium))
+                .foregroundStyle(Color.textMain.opacity(0.5))
+
+            Spacer(minLength: 0)
+
+            ProgressTrack(fraction: fraction, fill: state == .complete ? .success : Color.white)
+        }
+        .padding(.top, 12)
+        .padding(.bottom, 15)
+        .padding(.horizontal, 15)
+        .frame(height: 88)
+        .background(Color.backgroundRow, in: RoundedRectangle(cornerRadius: 6, style: .continuous))
+    }
+}
+
+/// The card's progress bar: a 10%-white track with a fill sized to `fraction`.
+private struct ProgressTrack: View {
+
+    let fraction: Double
+    let fill: Color
+
+    var body: some View {
+        GeometryReader { proxy in
+            ZStack(alignment: .leading) {
+                RoundedRectangle(cornerRadius: 2, style: .continuous)
+                    .fill(Color.white.opacity(0.1))
+
+                RoundedRectangle(cornerRadius: 2, style: .continuous)
+                    .fill(fill)
+                    .frame(width: proxy.size.width * CGFloat(max(0, min(1, fraction))))
+            }
+        }
+        .frame(height: 6)
+    }
+}