docs(patching): no dispatch in the last 15 minutes, running patches finish, 45 minute reboot wait

docs/vantage/patching.md

@@ -69,16 +69,20 @@ reports first, then reboots after one minute.
 
 Vantage then waits for the server to come back. The reboot counts as done when
 the agent reports a boot time later than the reboot, with no reboot still
-owed. A server that does not come back within 20 minutes is marked failed.
+owed. A server that does not come back within 45 minutes is marked failed.
 
 With **Never reboot**, the server shows **reboot required** instead.
 
 ## What happens during a window
 
 - Servers start patching as the window opens, up to the concurrency limit.
-- A server whose agent is offline is retried until the window closes.
-- Nothing new starts after the window closes. Servers already patching are
-  allowed to finish.
+- A server whose agent is offline is retried while the window is open.
+- No server starts patching in the last 15 minutes of a window. Servers still
+  waiting then are marked when the window closes.
+- Servers already patching are allowed to finish, even past the window end
+  (up to 2 hours from when each started). Interrupting a package manager is
+  worse than letting it finish late.
+- A reboot only happens if at least 5 minutes of the window remain.
 - A policy whose previous run is still going skips the window, and says so on
   the policy.