fix: surface bounded GPU admission failures

docs/deployment/shared-gpu-host.md

@@ -64,6 +64,12 @@ identity, or an invalid grant fails closed. Subsequent events include `resize`,
 `ready`, `heartbeat`, and `release`, with run/model identity, a monotonic
 sequence, process ID, timestamp, and measured allocator bytes.
 
+The host supervisor must finish its broker operation before the application's
+admission deadline. Reserve a safety margin for publishing a correlated denial
+and cleaning up a broker request that times out. Admission errors shown in the
+UI include safe run/event identifiers and deadline details; the service journal
+records the matching request, decision, and duration without lease credentials.
+
 The supervisor acknowledgment schema is:
 
 ```json