Onboarding step + Open /ui button + recording duration in footer

Three small UX wins:

1. Onboarding gained step 5 ('Run Teams headless') and step 6 ('Drive from another machine') so new operators discover the auto-launch/auto-hide + LAN-reachable workflows. Existing 'where things live' step renumbered to 7.

2. Settings → DISPLAY → Control surface URL row gains an Open button next to Copy that fires the URL into the default browser via Process.Start with UseShellExecute. Operators previewing how the embedded /ui control panel looks on a phone/tablet no longer need to copy-paste manually.

3. Recording badge in footer now shows 'REC 3 · 12:45' instead of just 'REC 3'. RecordingElapsed VM property maintains a separate timer from the session timer because recording can start AFTER the meeting begins; operators tracking 'how long has the archive copy been rolling' need that distinct duration.

src/TeamsISO.App/MainWindow.xaml

@@ -370,6 +370,8 @@
                                    VerticalAlignment="Center">
                             <Run Text="REC "/>
                             <Run Text="{Binding ActiveRecordingCount, Mode=OneWay}"/>
+                            <Run Text=" · "/>
+                            <Run Text="{Binding RecordingElapsed, Mode=OneWay}"/>
                         </TextBlock>
                     </StackPanel>
 
@@ -1367,14 +1369,24 @@
                                     <Grid.ColumnDefinitions>
                                         <ColumnDefinition Width="*"/>
                                         <ColumnDefinition Width="Auto"/>
+                                        <ColumnDefinition Width="Auto"/>
                                     </Grid.ColumnDefinitions>
                                     <TextBlock Grid.Column="0"
                                                Text="{Binding Settings.ControlSurfaceUrl}"
                                                Style="{StaticResource Wd.Text.Mono}"
                                                FontSize="11"
                                                Foreground="{DynamicResource Wd.Accent.Cyan}"
-                                               VerticalAlignment="Center"/>
+                                               VerticalAlignment="Center"
+                                               TextTrimming="CharacterEllipsis"/>
                                     <Button Grid.Column="1"
+                                            Style="{StaticResource Wd.Button.Ghost}"
+                                            Content="Open"
+                                            Command="{Binding Settings.OpenControlSurfaceCommand}"
+                                            Padding="10,2"
+                                            Margin="0,0,4,0"
+                                            FontSize="11"
+                                            ToolTip="Open this URL in your default browser. Useful for previewing how the control panel looks before pointing a phone or second-monitor at it."/>
+                                    <Button Grid.Column="2"
                                             Style="{StaticResource Wd.Button.Ghost}"
                                             Content="Copy"
                                             Command="{Binding Settings.CopyControlSurfaceUrlCommand}"

src/TeamsISO.App/OnboardingWindow.xaml

@@ -184,8 +184,8 @@
                         </StackPanel>
                     </Border>
 
-                    <!-- Step 5 — Where things live -->
+                    <!-- Step 5 — Headless Teams ("I only see TeamsISO") -->
-                    <Border Style="{StaticResource Wd.Card}" Padding="16">
+                    <Border Style="{StaticResource Wd.Card}" Padding="16" Margin="0,0,0,12">
                         <StackPanel>
                             <StackPanel Orientation="Horizontal" Margin="0,0,0,8">
                                 <Border Width="22" Height="22"
@@ -200,6 +200,62 @@
                                                HorizontalAlignment="Center"
                                                VerticalAlignment="Center"/>
                                 </Border>
+                                <TextBlock Text="Run Teams headless (optional)"
+                                           Style="{StaticResource Wd.Text.Heading}"
+                                           VerticalAlignment="Center"/>
+                            </StackPanel>
+                            <TextBlock TextWrapping="Wrap"
+                                       Style="{StaticResource Wd.Text.Body}"
+                                       FontSize="12"
+                                       Foreground="{DynamicResource Wd.Text.Secondary}"
+                                       Text="To use TeamsISO as your only window: tick both 'Launch Microsoft Teams on TeamsISO startup' and 'Auto-hide Teams windows when launched' under Settings → DISPLAY. Teams runs in the background; the IN-CALL bar shows the meeting state (READY / IN CALL · meeting title), the Mute/Camera/Share/Leave buttons drive Teams via UIAutomation, and the URL paste-box joins meetings directly. Use the eye-icon button in the left rail to manually restore Teams' windows when you need them."/>
+                        </StackPanel>
+                    </Border>
+
+                    <!-- Step 6 — Where things live -->
+                    <Border Style="{StaticResource Wd.Card}" Padding="16" Margin="0,0,0,12">
+                        <StackPanel>
+                            <StackPanel Orientation="Horizontal" Margin="0,0,0,8">
+                                <Border Width="22" Height="22"
+                                        CornerRadius="11"
+                                        Background="{DynamicResource Wd.Accent.CyanMuted}"
+                                        VerticalAlignment="Center"
+                                        Margin="0,0,12,0">
+                                    <TextBlock Text="6"
+                                               Foreground="{DynamicResource Wd.Accent.Cyan}"
+                                               FontFamily="{StaticResource Wd.Font.Mono}"
+                                               FontSize="12"
+                                               HorizontalAlignment="Center"
+                                               VerticalAlignment="Center"/>
+                                </Border>
+                                <TextBlock Text="Drive from another machine (optional)"
+                                           Style="{StaticResource Wd.Text.Heading}"
+                                           VerticalAlignment="Center"/>
+                            </StackPanel>
+                            <TextBlock TextWrapping="Wrap"
+                                       Style="{StaticResource Wd.Text.Body}"
+                                       FontSize="12"
+                                       Foreground="{DynamicResource Wd.Text.Secondary}"
+                                       Text="For headless host PC + thin-client setups: tick 'Control surface' then 'LAN-reachable' under DISPLAY. TeamsISO listens on http://&lt;your-lan-ip&gt;:9755/ui — open that URL from any browser on the LAN. First-time use needs a one-shot 'netsh http add urlacl url=http://+:9755/ user=Everyone' in an Administrator PowerShell."/>
+                        </StackPanel>
+                    </Border>
+
+                    <!-- Step 7 — Where things live -->
+                    <Border Style="{StaticResource Wd.Card}" Padding="16">
+                        <StackPanel>
+                            <StackPanel Orientation="Horizontal" Margin="0,0,0,8">
+                                <Border Width="22" Height="22"
+                                        CornerRadius="11"
+                                        Background="{DynamicResource Wd.Accent.CyanMuted}"
+                                        VerticalAlignment="Center"
+                                        Margin="0,0,12,0">
+                                    <TextBlock Text="7"
+                                               Foreground="{DynamicResource Wd.Accent.Cyan}"
+                                               FontFamily="{StaticResource Wd.Font.Mono}"
+                                               FontSize="12"
+                                               HorizontalAlignment="Center"
+                                               VerticalAlignment="Center"/>
+                                </Border>
                                 <TextBlock Text="If something breaks…"
                                            Style="{StaticResource Wd.Text.Heading}"
                                            VerticalAlignment="Center"/>

src/TeamsISO.App/ViewModels/GlobalSettingsViewModel.cs

@@ -95,8 +95,35 @@ public sealed class GlobalSettingsViewModel : ObservableObject
                 // Clipboard occasionally errors when something else has it locked.
             }
         });
+        OpenControlSurfaceCommand = new RelayCommand(() =>
+        {
+            // Hands the URL off to the OS shell so the user's default browser
+            // opens it. Operators previewing how the control panel looks on
+            // their phone / tablet / second monitor would otherwise have to
+            // copy-paste the URL — this is a one-click preview.
+            try
+            {
+                System.Diagnostics.Process.Start(new System.Diagnostics.ProcessStartInfo
+                {
+                    FileName = ControlSurfaceUrl,
+                    UseShellExecute = true,
+                });
+            }
+            catch (Exception ex)
+            {
+                _toast?.Warn($"Couldn't open: {ex.Message}");
+            }
+        });
     }
 
+    /// <summary>
+    /// Open the embedded HTML control panel (the <c>/ui</c> endpoint) in the
+    /// default browser. Enabled regardless of whether the control surface is
+    /// running — if it isn't, the browser will show a connection error, which
+    /// is informative; operators learn the surface needs to be enabled first.
+    /// </summary>
+    public RelayCommand OpenControlSurfaceCommand { get; }
+
     private void ResetOutputDefaults()
     {
         var confirm = MessageBox.Show(

src/TeamsISO.App/ViewModels/MainViewModel.cs

@@ -206,6 +206,21 @@ public sealed class MainViewModel : ObservableObject, IDisposable
     }
     private int _activeRecordingCount;
 
+    /// <summary>
+    /// Elapsed time since recording started this session, formatted as
+    /// "MM:SS" (or "HH:MM:SS" past an hour). Empty when nothing is
+    /// recording. Resets when all recordings stop, restarts on the next
+    /// rec-on transition. Useful for operators tracking "how long has the
+    /// show been rolling".
+    /// </summary>
+    public string RecordingElapsed
+    {
+        get => _recordingElapsed;
+        private set => SetField(ref _recordingElapsed, value);
+    }
+    private string _recordingElapsed = string.Empty;
+    private DateTimeOffset? _recordingStartedAt;
+
     /// <summary>True when the REST control surface (or OSC bridge, or both) is listening.</summary>
     public bool IsControlSurfaceRunning
     {
@@ -585,6 +600,25 @@ public sealed class MainViewModel : ObservableObject, IDisposable
         ActiveRecordingCount = _controller.RecordingEnabled ? enabledCount : 0;
         IsRecording = ActiveRecordingCount > 0;
 
+        // Recording session timer — independent of the global session timer
+        // since recording can start AFTER the meeting begins (or vice versa)
+        // and operators want to know exactly how long the archive copy has
+        // been rolling. Resets to null when all recordings stop, so the
+        // next rec-on transition starts the timer from 00:00.
+        if (IsRecording)
+        {
+            _recordingStartedAt ??= DateTimeOffset.UtcNow;
+            var recElapsed = DateTimeOffset.UtcNow - _recordingStartedAt.Value;
+            RecordingElapsed = recElapsed.TotalHours >= 1
+                ? $"{(int)recElapsed.TotalHours:D2}:{recElapsed.Minutes:D2}:{recElapsed.Seconds:D2}"
+                : $"{recElapsed.Minutes:D2}:{recElapsed.Seconds:D2}";
+        }
+        else
+        {
+            _recordingStartedAt = null;
+            RecordingElapsed = string.Empty;
+        }
+
         // Session timer — start on first ISO going live, reset when none are
         // live anymore. Subsequent enables after a full-zero gap restart the
         // timer rather than resuming, which is the operator's mental model: