CB-562: log why the readiness gate gave up on a target

bridged/src/main/java/dev/ltms/bridged/inject/Injector.java

@@ -78,6 +78,13 @@ public final class Injector {
      */
     private static final int READINESS_GRACE_POLLS = 240;
 
+    /**
+     * The cadence the poller drives {@link #onStatus} at, matched to {@code Bridged.INJECT_POLL_MILLIS}.
+     * This class holds no timing itself (it is driven by the poller), so this exists only to state
+     * the readiness grace in seconds on the CB-562 expiry log instead of hardcoding "60s".
+     */
+    private static final long POLL_INTERVAL_MILLIS = 250;
+
     private final AgentControl agents;
     private final TurnListener turnListener;
     private final Predicate<String> ready; // CB-113: a target is deliverable only when available
@@ -264,6 +271,11 @@ public final class Injector {
                             // fail every queued message and release the target (CB-114) instead of
                             // polling it indefinitely with the caller's future never completing.
                             notReady = new ArrayList<>(t.queue);
+                            log.warn("readiness grace for {} expired after {} polls ({}s): target never "
+                                    + "became deliverable, so failing {} queued message(s) that never "
+                                    + "reached its pane",
+                                    target, READINESS_GRACE_POLLS,
+                                    READINESS_GRACE_POLLS * POLL_INTERVAL_MILLIS / 1000, notReady.size());
                             t.queue.clear();
                             t.notReadySincePoll = 0;
                         }