nvrsion: Add: Fix tab bar animation delay when exiting session chat to ensure immediate slide-up (Models, AdaptiveRootView, SessionsView), update iOS settings to replace “Join a Mac’s group” with “Join an Orbital mesh” and add QR code button for device grouping.

Nucleic-Promote: 1
Co-authored-by: Nucleic <[email protected]>

NucleicRemote/NucleicRemote/Models/HostConnection.swift

@@ -92,6 +92,9 @@ final class HostConnection {
         var meshRosterChanged: () -> Void = {}
         /// The embedded Tailscale node's status changed (for Settings).
         var tailnetStatus: (String?, URL?) -> Void = { _, _ in }
+        /// A join code this host minted at our request ("add a device to this mesh") — the
+        /// `nucleic://pair?d=…` string to show as a QR / copyable code, or nil if it couldn't.
+        var pairingCodeReceived: (String?) -> Void = { _ in }
     }
     private let callbacks: Callbacks
 
@@ -593,6 +596,10 @@ final class HostConnection {
                 pinnedHost?.relayMembershipToken = membership.token
                 pinnedHost?.relayURL = membership.url
             }
+        case .pairingCode(let qr):
+            // This Mac minted a join code we asked for ("add a device to this mesh") — hand it up
+            // to RemoteStore for the QR/copy sheet.
+            callbacks.pairingCodeReceived(qr)
         case .wireError(let error):
             if error.code == .channelMismatch {
                 connectivity = .failed(error.message)

NucleicRemote/NucleicRemote/Models/RemoteStore.swift

@@ -66,11 +66,32 @@ final class RemoteStore: ObservableObject {
     private var openSessionHostID: String?
     @Published private(set) var openEvents: [AgentEvent] = []
     @Published private(set) var openApprovals: [ApprovalRequest] = []
+    /// Whether the compact (iPhone) Sessions tab currently has a session detail pushed. Distinct
+    /// from `openSessionID`, which is the *data* subscription and is only torn down on the detail's
+    /// `onDisappear` — and SwiftUI fires that at the *end* of the pop transition, so keying the
+    /// floating tab bar's visibility off it left the bar sliding back up 1–2s after a back-swipe.
+    /// `SessionsView` sets this straight from its navigation path, which flips the instant the pop
+    /// begins, so the bar reflows immediately while the transcript state survives the animation.
+    @Published var compactDetailPresented = false
     /// The open session's full diff (the Mac Diff tab's patch), fetched on demand when the
     /// user opens the Diff tab and the host advertises `canFetchDiff`. Nil until it arrives.
     @Published private(set) var openDiff: WireSessionDiff?
     @Published private(set) var diffLoading = false
 
+    /// "Add a device to this mesh" (Settings): the phone asks a connected Mac to mint a join code
+    /// and shows it as a QR / copyable link. The phone can't mint one itself (it runs no listener),
+    /// so this is always relayed through a live, capable host.
+    enum AddDeviceState: Equatable {
+        case idle
+        case requesting          // waiting on the host's `pairingCode` reply
+        case ready(String)       // the `nucleic://pair?d=…` join code to display
+        case unavailable         // no live host could mint one right now
+    }
+    @Published private(set) var addDevice: AddDeviceState = .idle
+    /// The host we asked to mint the current code, so a dismiss can tell the *same* Mac to close
+    /// its pairing window.
+    private var pairingMintHostID: String?
+
     /// A transient host-reported error (the mobile echo of the Mac's last-error bubble):
     /// shown as a red bubble at the bottom of the screen, auto-dismissed after a few seconds.
     struct LastError: Equatable, Identifiable {
@@ -533,6 +554,13 @@ final class RemoteStore: ObservableObject {
             self?.tailnetStatus = status
             self?.tailnetLoginURL = loginURL
         }
+        cb.pairingCodeReceived = { [weak self] qr in
+            guard let self else { return }
+            // Only apply while a request is outstanding — ignore a late reply after the user
+            // dismissed the sheet (we already told the host to cancel).
+            guard case .requesting = self.addDevice else { return }
+            self.addDevice = qr.map(AddDeviceState.ready) ?? .unavailable
+        }
         return cb
     }
 
@@ -664,6 +692,7 @@ final class RemoteStore: ObservableObject {
     /// aggregate and spin the embedded Tailscale node down.
     private func finishUnpairIfEmpty() {
         openSessionID = nil
+        compactDetailPresented = false
         openSessionHostID = nil
         openEvents = []; openApprovals = []; openDiff = nil; diffLoading = false
         connectivity = .unpaired
@@ -694,6 +723,7 @@ final class RemoteStore: ObservableObject {
         demoTasks.forEach { $0.cancel() }
         demoTasks.removeAll()
         openSessionID = nil
+        compactDetailPresented = false
         openSessionHostID = nil
         openEvents = []
         openApprovals = []
@@ -742,6 +772,44 @@ final class RemoteStore: ObservableObject {
         send(.fetchDiff(sessionID))
     }
 
+    // MARK: - Add a device to this mesh (relayed pairing-code mint)
+
+    /// Whether the "add a device" button should appear: a live Mac that advertises
+    /// `canMintPairingCode` is reachable to mint a join code (or we're in demo).
+    var canAddDeviceToMesh: Bool {
+        demoMode || pairingMintConnection != nil
+    }
+
+    /// The connection we route a mint request to: prefer the context host if it can mint, else any
+    /// live host that can. A code minted by *any* mesh member joins the whole group (mesh "join").
+    private var pairingMintConnection: HostConnection? {
+        if let ctx = contextConnection, ctx.connectivity.isLive, ctx.capabilities.canMintPairingCode {
+            return ctx
+        }
+        return connections.values.first { $0.connectivity.isLive && $0.capabilities.canMintPairingCode }
+    }
+
+    /// Ask a connected Mac to open a pairing window and hand back its join code. The reply arrives
+    /// asynchronously as `AddDeviceState.ready` (or `.unavailable`) via the host connection.
+    func requestPairingCode() {
+        if demoMode { addDevice = .ready(Self.demoPairingCode); return }
+        guard let conn = pairingMintConnection else { addDevice = .unavailable; return }
+        pairingMintHostID = conn.hostID
+        addDevice = .requesting
+        conn.send(.requestPairingCode)
+    }
+
+    /// The user dismissed the "add a device" sheet — tell the minting Mac to close its pairing
+    /// window (retire the one-time secret) and reset to idle.
+    func cancelPairingCode() {
+        if !demoMode, let id = pairingMintHostID { connections[id]?.send(.cancelPairingCode) }
+        pairingMintHostID = nil
+        addDevice = .idle
+    }
+
+    /// A stand-in join code for the offline demo so the QR/copy sheet renders without a Mac.
+    private static let demoPairingCode = "nucleic://pair?d=demo"
+
     /// Record that the user looked at this session now (clears its unseen-completion wash).
     func markOpened(_ sessionID: SessionID) {
         lastOpenedAt[sessionID] = Date()
@@ -936,9 +1004,12 @@ final class RemoteStore: ObservableObject {
             broadcastLive(msg)
 
         // Never originated from here (connection-internal, or handled by dedicated loops).
+        // `requestPairingCode`/`cancelPairingCode` are sent straight to the chosen host by
+        // `requestPairingCode()`/`cancelPairingCode()`, not through this owner-routing switch.
         case .hello, .ping, .listPeers, .addressUpdate, .meshRoster,
              .registerLiveActivity, .endLiveActivity,
-             .transferOffer, .transferChunk, .transferCommit, .transferCancel, .fetchTranscript:
+             .transferOffer, .transferChunk, .transferCommit, .transferCancel, .fetchTranscript,
+             .requestPairingCode, .cancelPairingCode:
             break
         }
     }
@@ -1046,7 +1117,10 @@ final class RemoteStore: ObservableObject {
              .registerLiveActivity, .endLiveActivity,
              // Session transfer (mesh P5) is a Mac↔Mac flow — the phone never originates these,
              // and demo has no peer Macs, so they're inert here.
-             .transferOffer, .transferChunk, .transferCommit, .transferCancel:
+             .transferOffer, .transferChunk, .transferCommit, .transferCancel,
+             // "Add a device" mint is handled directly against a live host, not via demoHandle;
+             // the demo path short-circuits in `requestPairingCode()` with a stand-in code.
+             .requestPairingCode, .cancelPairingCode:
             break  // passive / already handled by the seeded fixtures (demo has no mesh peers)
         }
     }

NucleicRemote/NucleicRemote/Views/AdaptiveRootView.swift

@@ -46,10 +46,13 @@ struct CompactRootView: View {
     @State private var barHeight: CGFloat = 72
 
     /// The bar owns the bottom edge on the top-level tabs, but yields it to a pushed session's
-    /// floating glass chat bar (`openSessionID`, set by `SessionDetailView`'s appear/disappear) and
+    /// floating glass chat bar (`compactDetailPresented`, driven by `SessionsView`'s navigation
-    /// to the new-chat composer while it's up (`showNewChat`) — both slide it out, so the composer
+    /// path) and to the new-chat composer while it's up (`showNewChat`) — both slide it out, so the
-    /// doesn't just stack on top of a lingering tab bar.
+    /// composer doesn't just stack on top of a lingering tab bar. We key off the path rather than
-    private var showsTabBar: Bool { store.openSessionID == nil && !showNewChat }
+    /// `openSessionID` because the path flips the instant a back-swipe begins, whereas
+    /// `openSessionID` isn't cleared until the detail's `onDisappear` fires at the *end* of the pop
+    /// transition — which left the bar sliding back up 1–2s late.
+    private var showsTabBar: Bool { !store.compactDetailPresented && !showNewChat }
 
     /// The "+" is inert without control scope or a project to start in, so it's shown only when a
     /// chat could actually be kicked off (mirrors `NewChatAffordance.canStart`).

NucleicRemote/NucleicRemote/Views/SessionsView.swift

@@ -73,9 +73,18 @@ struct SessionsView: View {
                     path.append(SessionID(rawValue: raw))
                 }
                 consumeRoute()
+                // Sync the shell's tab-bar visibility to the current push depth on (re)appear —
+                // `onChange` alone won't fire for a path restored across a remount.
+                store.compactDetailPresented = !path.isEmpty
             }
             // A notification tap while this tab is already up.
             .onChange(of: store.pendingRoute) { consumeRoute() }
+            // Drive the floating tab bar straight off the navigation path: it empties the instant a
+            // back-swipe/tap begins, so the bar slides back in immediately instead of waiting for
+            // `SessionDetailView.onDisappear` (which fires only at the end of the pop transition).
+            .onChange(of: path) { _, newPath in
+                store.compactDetailPresented = !newPath.isEmpty
+            }
             .toolbar {
                 ToolbarItem(placement: .topBarTrailing) {
                     Button {

NucleicRemote/NucleicRemote/Views/SettingsView.swift

@@ -1,4 +1,5 @@
 import SwiftUI
+import CoreImage.CIFilterBuiltins
 import NucleicProtocol
 import NucleicTailnet
 import UIKit
@@ -7,6 +8,7 @@ struct SettingsView: View {
     @EnvironmentObject var store: RemoteStore
     @State private var showScanner = false
     @State private var showManualPair = false
+    @State private var showAddDevice = false
     /// Bumped after removing a paired Mac so the "Paired Macs" list re-reads the registry (mesh P3).
     @State private var pairedHostsToken = UUID()
     @AppStorage("nucleic.showRawEvents") private var showRaw = false
@@ -138,10 +140,20 @@ struct SettingsView: View {
                 }
 
                 Section {
+                    // Grow the mesh: ask a connected Mac to mint a join code this phone shows —
+                    // scan it from a new iPhone/iPad, or copy the link to a new Mac. Only when a
+                    // live Mac can mint one (the phone can't originate a join code on its own).
+                    if store.canAddDeviceToMesh {
+                        Button {
+                            showAddDevice = true
+                        } label: {
+                            Label("Add a device to this mesh", systemImage: "plus.circle")
+                        }
+                    }
                     Button {
                         showScanner = true
                     } label: {
-                        Label("Join a Mac's group", systemImage: "qrcode.viewfinder")
+                        Label("Join an Orbital mesh", systemImage: "qrcode.viewfinder")
                     }
                     Button {
                         showManualPair = true
@@ -171,6 +183,9 @@ struct SettingsView: View {
                     store.pair(with: payload)
                 }
             }
+            .sheet(isPresented: $showAddDevice, onDismiss: { store.cancelPairingCode() }) {
+                AddDeviceView()
+            }
         }
     }
 
@@ -355,3 +370,118 @@ struct ManualPairingView: View {
         dismiss()
     }
 }
+
+/// "Add a device to this mesh": the phone can't mint a join code itself (it runs no listener), so
+/// it asks a connected Mac to open a pairing window and relays back that Mac's code — shown here as
+/// a QR to scan from a new iPhone/iPad, or a copyable link to send to a new Mac. Scanning/pasting it
+/// joins the new device to the whole group. Dismissing the sheet closes the Mac's pairing window
+/// (`RemoteStore.cancelPairingCode`, wired to the sheet's `onDismiss`).
+struct AddDeviceView: View {
+    @EnvironmentObject var store: RemoteStore
+    @Environment(\.dismiss) private var dismiss
+    @State private var copied = false
+    @State private var copyResetTask: Task<Void, Never>?
+
+    var body: some View {
+        NavigationStack {
+            Form {
+                switch store.addDevice {
+                case .idle, .requesting:
+                    Section {
+                        HStack {
+                            ProgressView()
+                            Text("Asking a Mac in your mesh for a join code…")
+                                .foregroundStyle(.secondary)
+                        }
+                    }
+                case .unavailable:
+                    Section {
+                        Label("Couldn't get a join code", systemImage: "exclamationmark.triangle.fill")
+                            .foregroundStyle(.orange)
+                        Text("This needs a Mac in your mesh that's connected right now. Make sure "
+                             + "one is reachable with its meshing service on, then try again.")
+                            .font(.callout).foregroundStyle(.secondary)
+                        Button("Try again") { store.requestPairingCode() }
+                    }
+                case .ready(let code):
+                    codeSection(code)
+                }
+            }
+            .navigationTitle("Add a device")
+            .navigationBarTitleDisplayMode(.inline)
+            .toolbar {
+                ToolbarItem(placement: .confirmationAction) { Button("Done") { dismiss() } }
+            }
+        }
+        // Fire the request as the sheet appears; `onDismiss` (on the presenter) tells the Mac to
+        // close its pairing window.
+        .onAppear { if case .ready = store.addDevice {} else { store.requestPairingCode() } }
+        .onDisappear { copyResetTask?.cancel() }
+    }
+
+    @ViewBuilder
+    private func codeSection(_ code: String) -> some View {
+        Section {
+            if let image = Self.qrImage(code) {
+                HStack {
+                    Spacer()
+                    Image(uiImage: image)
+                        .interpolation(.none)
+                        .resizable()
+                        .frame(width: 220, height: 220)
+                        .padding(10)
+                        .background(.white, in: RoundedRectangle(cornerRadius: 12))
+                    Spacer()
+                }
+                .listRowBackground(Color.clear)
+            }
+        } header: {
+            Text("Scan to join")
+        } footer: {
+            Text("On a new iPhone or iPad, open Nucleic Remote ▸ Join an Orbital mesh and scan this. "
+                 + "It joins the whole group — every Mac and device here.")
+        }
+
+        Section {
+            Text(code)
+                .font(.system(.caption, design: .monospaced))
+                .lineLimit(2)
+                .truncationMode(.middle)
+                .textSelection(.enabled)
+            Button {
+                copyCode(code)
+            } label: {
+                Label(copied ? "Copied" : "Copy join code",
+                      systemImage: copied ? "checkmark" : "doc.on.doc")
+            }
+        } header: {
+            Text("Or send a code")
+        } footer: {
+            Text("Paste into “Join mesh…” on another Mac, or “Enter code manually” on an iPhone or "
+                 + "iPad. A Mac joining is confirmed on the Mac that shared the code.")
+        }
+    }
+
+    private func copyCode(_ code: String) {
+        UIPasteboard.general.string = code
+        withAnimation(.easeOut(duration: 0.12)) { copied = true }
+        copyResetTask?.cancel()
+        copyResetTask = Task {
+            try? await Task.sleep(for: .seconds(1.4))
+            guard !Task.isCancelled else { return }
+            withAnimation(.easeIn(duration: 0.2)) { copied = false }
+        }
+    }
+
+    /// Render the join string as a QR code (CoreImage), mirroring the Mac's pairing sheet.
+    private static func qrImage(_ string: String) -> UIImage? {
+        let filter = CIFilter.qrCodeGenerator()
+        filter.message = Data(string.utf8)
+        filter.correctionLevel = "M"
+        guard let output = filter.outputImage else { return nil }
+        let scaled = output.transformed(by: CGAffineTransform(scaleX: 10, y: 10))
+        let context = CIContext()
+        guard let cg = context.createCGImage(scaled, from: scaled.extent) else { return nil }
+        return UIImage(cgImage: cg)
+    }
+}