Post-update-reboot RDP outage fixed: waitforx shim + xbrlapi hook (#611)

Two reboot-triggered session killers: xrdp waitforx RandR race/empty-argv
(shim wrapper; pristine = waitforx.real) and 90xbrlapi foreground hang
(hook disabled). new_cursors=false for the cursor box. Re-apply via
17-fix-rdp-postupdate.sh. Full diagnosis:
https://projects.knownelement.com/issues/611#note-4513

💘 Generated with Crush

Assisted-by: Crush:glm-5.2

NEXT.md

@@ -1,5 +1,17 @@
 # NEXT — perf-opt closeout COMPLETE (2026-08-31); #610 open-terminal fleet DONE
 
+## 2026-09-05 early AM — post-update-reboot RDP outage FIXED (#611)
+- Two reboot-triggered killers: waitforx RandR race/empty-argv (shim at
+  /usr/lib/x86_64-linux-gnu/xrdp/waitforx, pristine = waitforx.real) and
+  90xbrlapi foreground hang (hook disabled). Re-apply after xrdp/brltty
+  package upgrades: sudo ./17-fix-rdp-postupdate.sh
+- new_cursors=false live (cursor black box; pairs with #631 core cursors).
+- LESSON: never bounce the xrdp front-end while a session lives — sesman
+  orphans the record and the next login spawns a SECOND KDE session on the
+  shared user bus (dual-plasma conflict). Recovery = kill all session
+  processes, verify zero plasma, reconnect once.
+- Human UAT: desktop confirmed working post-fix; cursor-box verdict pending.
+
 ## Tonight (2026-08-31 late, crush had the con)
 - Agent-stack relaunchers REMOVED (6-): no screen/crush sessions auto-start
   on reboot, any account. Backups: removed-agent-stacks/.