docs: refresh desktop egress command docs

docs/commands/desktop.md

@@ -7,6 +7,7 @@ over VNC manually.
 crabbox warmup --desktop --browser
 crabbox desktop launch --id blue-lobster --browser --url https://example.com
 crabbox desktop launch --id blue-lobster --browser --url https://example.com --webvnc --open
+crabbox desktop launch --id blue-lobster --browser --url https://discord.com/login --egress discord --webvnc --open
 crabbox desktop launch --id blue-lobster -- xterm
 ```
 
@@ -19,6 +20,13 @@ into the authenticated WebVNC portal. Add `--open` to open that portal locally.
 Browser launches default to a windowed human desktop with the remote panel and
 title bar visible; use `--fullscreen` only for capture/video workflows.
 
+`--egress <profile>` passes the active lease-local egress proxy to the launched
+browser as `--proxy-server=http://127.0.0.1:3128`, so the browser exits to the
+internet through the operator machine running `crabbox egress start`. Start
+the egress bridge first; the flag currently requires `--browser`. Override the
+proxy address with `--egress-proxy host:port` if you started egress on a
+non-default port. See [egress](egress.md) for the full bridge model.
+
 On Windows, SSH sessions cannot directly own the visible console desktop, so
 Crabbox writes a one-shot PowerShell launcher under `C:\ProgramData\crabbox` and
 runs it as an interactive scheduled task for the logged-in `crabbox` user. The
@@ -42,5 +50,15 @@ Flags:
 --webvnc
 --open
 --fullscreen
+--egress <profile>
+--egress-proxy <host:port>
 --reclaim
 ```
+
+Related docs:
+
+- [egress](egress.md)
+- [vnc](vnc.md)
+- [webvnc](webvnc.md)
+- [Lease capabilities](../features/capabilities.md)
+- [Mediated egress](../features/egress.md)