diff --git a/fleetd/src/main/java/dev/ltms/fleet/session/SessionManager.java b/fleetd/src/main/java/dev/ltms/fleet/session/SessionManager.java
index 5ffa5b8..75ab15c 100644
--- a/fleetd/src/main/java/dev/ltms/fleet/session/SessionManager.java
+++ b/fleetd/src/main/java/dev/ltms/fleet/session/SessionManager.java
@@ -864,10 +864,20 @@ public final class SessionManager implements TurnListener {
     }
 
     /**
-     * Gracefully drain all registered sessions on daemon shutdown. For each session that is
-     * {@code BUSY}, poll up to {@code timeoutNanos} for it to leave {@code BUSY}, then release it
-     * regardless. Non-busy sessions are released immediately. A failure releasing one session is
-     * logged and does not abort the rest.
+     * Gracefully drain all registered sessions on daemon shutdown. Non-busy sessions are released
+     * immediately; a {@code BUSY} one is polled until it leaves {@code BUSY}, then released
+     * regardless. A failure releasing one session is logged and does not abort the rest.
+     *
+     * <p>{@code timeoutNanos} is a budget for the WHOLE drain, not a grace period per session: the
+     * deadline is taken once, before the loop. So the first BUSY session can spend all of it, and a
+     * later BUSY one is then released with no wait at all. That is deliberate. This drain is only
+     * one phase of shutdown — {@code Fleetd} closes the message service, the push loop, the
+     * heartbeat, MCP and the router after it — and the whole sequence has to finish inside
+     * launchd's exit window. A per-session grace would let N busy members drain for N * the
+     * timeout, overrun that window, and get the daemon SIGKILLed part-way through; the members not
+     * yet reached would then get no clean release, no preserved-worktree log, and no snapshot.
+     * Cutting one turn short is the cheaper failure, and it is not silent: an abandoned BUSY
+     * session is preserved, snapshotted, and logged at WARN by {@code logPreservedForShutdown}.
      *
      * <p>CB-544: this is a {@link ReleaseCause#SHUTDOWN} release — the worker's pane is stopped
      * (the process must end) but its worktree is preserved and its path logged. Shutdown is never