fix(process): scope the escalation claim to ticks, and pin the boundary

Review round 1, one finding, accepted.

"A failed escalation is never retried by anything" was false.
`shutdown()`'s force-kill loop iterates the reap ledger with **no**
`!entry.killed` guard, so it does re-kill an entry the escalation arm
gave up on. The accurate claim is that no later *tick* retries it —
`tick_reap_ledger`'s escalation is guarded by `!entry.killed` and never
fires again for that group.

The overclaim collapsed two failure modes that this lane exists to keep
distinct: a failed escalation leaks the group until editor exit, where
one more attempt is made, while a failed `shutdown()` force-kill leaks
it past exit with nothing left to try. Narrowed in the framing, the
handoff, the active-work ledger and the test commentary.

The corrected claim was asserted in three documents and pinned by
nothing, so it gets a pin: a failed escalation marks the entry, the
survivor stays alive across ticks, and `shutdown()` — with no fault
planned, so its force-kill really lands — still reaps it. Bitten by
adding the missing `!entry.killed` guard to that loop: the new pin
fails and the other five stay green.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01Lv428Fth9LRtffwJSsqH7T

docs/active-work.md

@@ -363,10 +363,15 @@ compatible.
   justified the ledger's leniency and deliberately changed no
   disposition; this lane owns what it refused.
 - **Four sites, not the two #200 named.** In the persistent ledger: a
-  probe error of any errno drops the entry and cancels escalation; a failed escalating
+  probe error of any errno drops the entry and cancels escalation; a
-  `SIGKILL` is marked as succeeded and never retried; and `shutdown()`
+  failed escalating `SIGKILL` is marked as succeeded, so **no later tick
-  discards its own force-kill result the same way — on the path that
+  retries it**; and `shutdown()` discards its own force-kill result the
-  exists specifically to stop a leak at editor exit. **Plus the in-drain
+  same way — on the path that exists specifically to stop a leak at
+  editor exit. Those last two are **distinct, not cumulative**:
+  `shutdown()` force-kills every entry with no `!entry.killed` guard, so
+  a failed escalation still gets one attempt at exit, while a failed
+  force-kill leaks the group past exit with nothing left to try.
+  **Plus the in-drain
   twin** `final_drain_runtime`, which collapses every errno to "dead"
   while no tick runs; a false "dead" there cancels the readers, so its
   failure mode is truncated output rather than a leaked process.

docs/agent-handoff.md

@@ -267,9 +267,17 @@ commands, read `docs/active-work.md` immediately after this file.
     correct) from any other errno (we could not ask — not correct), and
     `retain` deletes the entry either way, cancelling escalation.
   - The deadline escalation sets `killed = true` whether or not the
-    `SIGKILL` landed, so a failed one is **never retried by anything**.
+    `SIGKILL` landed, so **no later tick retries it** — that arm is
-  - `shutdown()`'s force-kill does the same, on the path written
+    guarded by `!entry.killed` and never fires again for the group.
-    specifically to stop a leak at editor exit.
+  - `shutdown()`'s force-kill discards its result the same way, on the
+    path written specifically to stop a leak at editor exit. **It is not
+    the same failure**, and the difference is the retry: `shutdown()`
+    iterates the ledger with *no* `!entry.killed` guard, so it does
+    re-kill an entry the escalation arm marked. A failed escalation
+    leaks the group until editor exit, where one more attempt is made; a
+    failed force-kill leaks it *past* editor exit, with nothing left to
+    try. Saying the escalation is "never retried by anything" collapses
+    the two.
   - `final_drain_runtime`'s twin collapses every errno into "dead",
     which quiesces the drain and **cancels the readers** — truncated
     output rather than a leaked process, and terminal for that drain

docs/reap-ledger-silent-failures-framing.md

@@ -169,7 +169,23 @@ behaviour is unchanged: an `EPERM` probe is indistinguishable from
 `ESRCH`.
 
 **(b)** A failed `SIGKILL` is recorded as a successful one. The entry
-then satisfies `!entry.killed == false` forever and is never retried.
+then satisfies `!entry.killed == false` forever, so **no later tick
+retries it** — the escalation arm is guarded by `!entry.killed` and
+never fires again for that group.
+
+**Scoped to ticks, and the scope matters.** `shutdown()`'s force-kill
+loop (c) iterates the ledger with **no `!entry.killed` guard**, so it
+*does* re-kill an entry this arm marked. The two failure modes are
+therefore distinct rather than cumulative:
+
+| Failure | Survivor lives until |
+|---|---|
+| escalation `SIGKILL` fails | editor exit, where `shutdown()` gets one more attempt |
+| `shutdown()` force-kill fails | past editor exit — nothing else tries |
+
+Saying (b) is "never retried by anything" would collapse that
+distinction and overstate it: the one remaining attempt is exactly what
+(c) is, and (c)'s own failure is a different and worse outcome.
 
 **(c) `shutdown()` has the same discard** (`:1763-1766`), on the path
 that exists specifically to stop a leak at editor exit:
@@ -381,8 +397,9 @@ noted so a red run on it is not mistaken for this lane's doing.*
 
 - **Bet 2 — each silent consequence is demonstrable once injectable.**
   With the seam: an `EPERM` probe drops an entry whose group is still
-  alive; a failed `SIGKILL` leaves `killed = true` and is never retried;
+  alive; a failed `SIGKILL` leaves `killed = true` so no later **tick**
-  `shutdown()`'s discard does the same at exit; and a continuously false
+  retries it; `shutdown()`'s discard leaks the group past editor exit,
+  which is a different and worse outcome; and a continuously false
   in-drain probe cancels readers before a live descendant's deliberately
   late output can arrive.
   - *Falsified if* any of the three turns out to be unreachable in

src/process.rs

@@ -4649,8 +4649,16 @@ mod tests {
     fn a_failed_escalation_is_recorded_as_a_successful_one() {
         // §1.2 (b). `entry.killed = true` runs unconditionally, so a
         // SIGKILL that never landed satisfies `!entry.killed == false`
-        // forever. The consequence is not bookkeeping: the survivor is
+        // forever. The consequence is not bookkeeping: **no later tick
-        // never killed again, by anything.
+        // retries it**, so the survivor outlives every escalation the
+        // ledger will ever attempt during the session.
+        //
+        // Scoped to ticks deliberately. `shutdown()`'s force-kill loop
+        // iterates the ledger with **no `!entry.killed` guard**, so it
+        // does re-kill an entry this arm marked — which is why that
+        // failure mode is distinct and has its own pin. This one ticks
+        // and never calls `shutdown`, so what it asserts is exactly
+        // what it says.
         let dir = tempfile::tempdir().expect("tempdir");
         let mut sup = ProcessSupervisor::new();
         sup.set_group_term_grace(Duration::from_millis(150));
@@ -4683,11 +4691,61 @@ mod tests {
             pid_alive(survivor),
             "no tick ever retries the failed SIGKILL, so the survivor outlives the ledger's only escalation"
         );
-        assert_eq!(sup.reap_ledger_len(), 1, "the entry is retained, and inert");
+        assert_eq!(
+            sup.reap_ledger_len(),
+            1,
+            "the entry is retained, and inert to every subsequent tick"
+        );
         sup.assert_reap_faults_consumed();
         reap_fixture_survivor(survivor);
     }
 
+    #[test]
+    fn shutdown_still_force_kills_a_group_a_failed_escalation_marked_killed() {
+        // The boundary of the pin above, and the reason its claim is
+        // "no later TICK retries it" rather than "nothing retries it".
+        //
+        // `shutdown()`'s force-kill loop iterates the ledger with no
+        // `!entry.killed` guard, so the one thing that still acts on an
+        // entry the escalation arm gave up on is editor exit. That
+        // keeps the two failure modes distinct: a failed escalation
+        // leaks the group until exit; a failed force-kill leaks it
+        // past exit.
+        //
+        // No fault is planned for the shutdown site here — the whole
+        // point is that this force-kill really lands.
+        let dir = tempfile::tempdir().expect("tempdir");
+        let mut sup = ProcessSupervisor::new();
+        sup.set_group_term_grace(Duration::from_millis(150));
+        let (script, pidfile) = survivor_script(dir.path(), true);
+        let id = sup
+            .spawn(sh_group_spec("escalation-then-shutdown", &script))
+            .expect("spawn");
+        let events = drain_until(&mut sup, id, Duration::from_secs(5), has_exited);
+        let pgid = i32::try_from(started_pid(&events).expect("leader pid")).expect("pgid fits");
+        let survivor = wait_pidfile(&pidfile);
+
+        sup.plan_reap_kill_failure(ReapKillSite::LedgerEscalation, nix::errno::Errno::EPERM);
+        std::thread::sleep(Duration::from_millis(250));
+        sup.tick();
+        assert_eq!(
+            sup.reap_ledger_killed(pgid),
+            Some(true),
+            "precondition: the entry is marked killed by a SIGKILL that failed"
+        );
+        assert!(pid_alive(survivor), "precondition: the survivor is alive");
+
+        sup.shutdown();
+
+        assert!(
+            !pid_alive(survivor),
+            "shutdown force-kills every armed entry, marked or not — so an escalation \
+             failure is not the survivor's last reprieve"
+        );
+        assert_eq!(sup.reap_ledger_len(), 0, "and the entry probes to ESRCH");
+        sup.assert_reap_faults_consumed();
+    }
+
     #[test]
     fn a_failed_shutdown_force_kill_leaks_the_group_and_burns_the_bound() {
         // §1.2 (c). The path that exists specifically to stop a leak at