fleetd #494 follow-up (2nd pass): the grace-release line still had one constant, and its test could not tell the difference

Two more fixes on the same line, LeadRollover.java:600-624:

1. The poll-count argument (second, was PICKUP_GRACE_POLLS) now prints the
   loop's own idlePollsAwaitingPickup counter instead of the constant. Same
   defect shape as the nudges fix from c87cc25, one argument over.

2. LeadRolloverTest's clearGraceReleaseLogIsWarnWithMeasuredElapsed asserted
   its nudge-count expectation as `LeadRollover.PICKUP_GRACE_POLLS - 1` — the
   same expression the production code used to build the log line from, so it
   could not discriminate a reverted fix. Rewritten to plain literals
   ("after 8 consecutive IDLE/DONE polls (7 of those were nudged)"), proven to
   trip when PICKUP_GRACE_POLLS's value changes (2 failures under a
   PICKUP_GRACE_POLLS=5 mutation: this test and successLogPrintsMeasured...).

Also corrected the comment above the log line: idlePollsAwaitingPickup and
nudges each have exactly one write site on this loop's release branch, so they
cannot differ from PICKUP_GRACE_POLLS / PICKUP_GRACE_POLLS - 1 at this call
site — confirmed by re-deriving the loop's control flow, and by reverting just
the nudges argument (M1) and observing 33/0 stayed green even after the test
rewrite. That is an equivalent mutant on this line, not a gap the test rewrite
could close; the honest value of printing the counters is one source of truth
for the loop, not a provable-by-test difference here. The place nudges truly
varies with the run — and is covered by a test that can tell it apart from a
constant — is the /clear-timeout warn's clearResult.nudges() in runRollover.

mvn -Dtest=LeadRolloverTest test: 33/0. mvn clean install: 1681/0, BUILD SUCCESS.

Same-shape sweep (found, not fixed, per instructions):
Injector.java:383-387 — the readiness-grace warn prints the constant
READINESS_GRACE_POLLS where the measured per-target counter
t.notReadySincePoll is in scope (single increment site, just reached the
threshold at this call site — same equivalent-mutant situation as this fix).

fleetd/src/main/java/dev/ltms/fleet/lead/LeadRollover.java

@@ -605,18 +605,22 @@ public final class LeadRollover {
                     // whole roll "succeeded" after 438ms of a 20s budget), so raise it to WARN and
                     // print the MEASURED elapsed time next to the target pane, not just the count.
                     //
-                    // fleetd #494 follow-up: the nudge count printed here must be the MEASURED
-                    // `nudges` counter, never the constant `PICKUP_GRACE_POLLS - 1` — the constant
-                    // happens to equal it today (this branch only fires after exactly
-                    // PICKUP_GRACE_POLLS - 1 nudges), but a mutation test caught this exact
-                    // expression once already printing the wrong constant (PICKUP_GRACE_POLLS
-                    // itself, claiming 8 nudges where 7 went out) and a plain code read did not
-                    // catch it. Printing the counter cannot drift from the loop's real behaviour,
-                    // whatever changes later to PICKUP_GRACE_POLLS or the loop itself.
+                    // fleetd #494 follow-up (2nd pass): BOTH numbers in this line must come from
+                    // the loop's own counters, never from the PICKUP_GRACE_POLLS constant.
+                    // `idlePollsAwaitingPickup` and `nudges` each have exactly one write site in
+                    // this loop, on the same branch, so on this branch they cannot differ from
+                    // PICKUP_GRACE_POLLS / PICKUP_GRACE_POLLS - 1 today — no test can prove the
+                    // difference on this line, and printing the counters does not change that.
+                    // What it does buy: one source of truth instead of two, so a later change to
+                    // the loop (an early return, a second increment site, a different exit
+                    // condition) cannot leave this message reporting a number the loop no longer
+                    // produces. The place where `nudges` genuinely varies with the run — and is
+                    // covered by a test that can tell it apart from a constant — is the
+                    // /clear-timeout warn in runRollover, which prints clearResult.nudges().
                     log.warn("lead-rollover: /clear on {} was never observed as WORKING after {} "
                                     + "consecutive IDLE/DONE polls ({} of those were nudged) — "
                                     + "releasing rather than wedging the roll (elapsed={}ms)",
-                            target, PICKUP_GRACE_POLLS, nudges, elapsedMillis);
+                            target, idlePollsAwaitingPickup, nudges, elapsedMillis);
                     return new ClearSettleResult(true, elapsedMillis, nudges);
                 }
                 try {

fleetd/src/test/java/dev/ltms/fleet/lead/LeadRolloverTest.java

@@ -971,14 +971,17 @@ class LeadRolloverTest {
             assertTrue(message.contains("elapsed=4500ms"), "must print the MEASURED elapsed time — "
                     + "with this fixture's advancing clock, the wait ran 4500ms before releasing: "
                     + message);
-            // fleetd #494 follow-up: the nudge count in this line must be the MEASURED counter, not
-            // the constant PICKUP_GRACE_POLLS - 1 that used to stand in for it — the two happen to
-            // agree today, but only the counter cannot drift from the loop's real behaviour if
-            // PICKUP_GRACE_POLLS or the loop ever changes. Reference the constant here (rather than
-            // hardcoding "7") so this assertion itself does not silently stop discriminating if
-            // PICKUP_GRACE_POLLS changes later.
-            assertTrue(message.contains("(" + (LeadRollover.PICKUP_GRACE_POLLS - 1) + " of those were nudged)"),
-                    "must print the measured nudge count: " + message);
+            // fleetd #494 follow-up (2nd pass): both numbers here are DELIBERATE plain literals,
+            // not derived from LeadRollover.PICKUP_GRACE_POLLS. A version of this assertion that
+            // reads "(" + (LeadRollover.PICKUP_GRACE_POLLS - 1) + " of those were nudged)" builds
+            // its expectation the same way the production code used to build the log line, so it
+            // cannot tell a fixed constant apart from the measured counter — proved by reverting
+            // the production fix and re-running: that mutant stayed green under the old assertion.
+            // If PICKUP_GRACE_POLLS ever changes, THIS TEST MUST FAIL and a human must look at the
+            // new message and update the literals below, not just re-derive them.
+            assertTrue(message.contains("after 8 consecutive IDLE/DONE polls (7 of those were nudged)"),
+                    "must print the measured poll count and nudge count as plain numbers, not the "
+                            + "PICKUP_GRACE_POLLS constant standing in for either: " + message);
         } finally {
             detachLog(events);
         }