Reparents Teams' main top-level window into a TeamsISO-owned host via Win32 SetParent + window-style stripping. Operator gets Teams visually INSIDE TeamsISO instead of as a separate window — completes the 'Teams runs within this app' direction the user asked for after auto-hide.
Strictly opt-in (DISPLAY tab → 'Embed Teams window (experimental)'). Modern Teams runs WebView2 in its main window; WebView2 is sensitive to parent changes and may render glitches or refuse focus. If so, operator unticks and falls back to auto-hide mode.
Implementation:
- TeamsLauncher.EmbedTeamsInto(hostHwnd, w, h): finds Teams' main window (longest-title heuristic — same as GetActiveWindowTitle), saves original parent + WS_STYLE, SetParents into host, strips WS_CAPTION + WS_THICKFRAME + WS_BORDER + WS_DLGFRAME + WS_POPUP, adds WS_CHILD, MoveWindow to fit.
- TeamsLauncher.RestoreEmbed(): SetParent back to desktop + restore saved window styles. Idempotent — safe to call on shutdown even if nothing was embedded.
- TeamsLauncher.ResizeEmbedded(w, h): MoveWindow to new dimensions; called from host SizeChanged event.
- New TeamsEmbedWindow chromeless host with an EXPERIMENTAL pill in the caption. Loaded → grab HwndSource from EmbedHost Border → call EmbedTeamsInto. SizeChanged → ResizeEmbedded. Closed → RestoreEmbed (in try/finally so a crash can't leave Teams orphaned). Friendly fallback messages if no Teams window exists or HWND grab fails.
- Settings → DISPLAY → checkbox + 'Open embed window' button (gated by the checkbox). Persisted via EmbedTeamsWindow on UIPreferences.
New AutoRecordOnCall preference (DISPLAY tab). When checked, recording auto-flips ON the moment Teams transitions into a call (UIA Leave button appears in tree), and auto-flips OFF when the call ends.
Completes the unattended-show story: with Launch + AutoHide + AutoRecord all ticked, the operator launches TeamsISO and walks away — Teams runs invisibly, recording begins/ends with the meeting, ISOs route, all done. Toast surfaces each transition so they know what's happening if they glance at the screen.
Implementation: transition detection lives in the existing UIA-probe code in OnStatsTick. previousInCall != inCall gate prevents the auto-toggle from re-firing on every poll. Direct call to _controller.SetRecording + Settings.RecordIsosToDisk = ... so the existing recording infrastructure handles the rest. Toast for visibility, swallow-on-error so a recording config issue can't break the IN-CALL pill update path.
Two new persisted preferences in DISPLAY settings, paired to give operators the 'launch TeamsISO, never see Teams' experience the user asked for:
- LaunchTeamsOnStartup: TeamsISO auto-starts Teams in the background each launch (fire-and-forget background task in App.OnStartup, after the main window has materialized so a slow Teams launch doesn't delay the UI).
- AutoHideTeamsWindows: as soon as Teams' windows materialize after launch, hide them. New TeamsLauncher.AutoHideAfterLaunchAsync runs a polling loop (250ms / up to 15s) that catches the splash, main window, and any follow-up panels Teams opens. Teams takes 2-5s to render its main window and the splash arrives separately, so a one-shot hide right after launch wouldn't be enough.
When TeamsISO starts and Teams is already running (from a prior session), the auto-hide path still fires so the 'I only see TeamsISO' rule applies even when Teams was launched externally.
Operator drives everything through the IN-CALL bar (mute / camera / share / leave / marker) + participants DataGrid (ISO routing). Eye-toggle in the rail still restores Teams windows on demand.
Both toggles default to off — opt-in. Persisted via UIPreferences so they survive process restart.
When the new ControlSurfaceLanReachable preference is on, both the REST/WebSocket control surface and the OSC bridge bind to all interfaces (http://+:port/ via HttpListener wildcard, IPAddress.Any for OSC) instead of loopback. The settings VM persists the toggle, restarts both surfaces when flipped, and surfaces a ControlSurfaceUrl computed from the first non-loopback IPv4 + a Copy button so operators can paste the URL onto a control PC.
Use case: a headless host PC runs Teams + TeamsISO; a thin client on the same LAN drives it via /ui or a Stream Deck. Closed-network deployment, no auth — documented as a trusted-LAN-only mode in docs/CONTROL-SURFACE.md, including the one-time 'netsh http add urlacl url=http://+:9755/ user=Everyone' requirement and the firewall rule.
