refactor(cron): trim will_retry docstring and rename its yield test

WHY: the salvaged docstring narrated the incident and referenced another PR;
replace it with the invariant the predictor must hold. The test only covers
the yield branch, so drop "terminal_paths" from its name.

cron/unreachable_retry.py

@@ -68,26 +68,9 @@ def _is_recurring(job: Dict[str, Any]) -> bool:
 
 
 def will_retry(job: Dict[str, Any]) -> bool:
-    """Predict whether ``plan_retry`` will schedule a re-run for this flagged failure —
-    used by the scheduler to suppress the interim failure notice.
-
-    Must mirror ``plan_retry`` (and the ``mark_job_run`` guards around it) decision-for-
-    decision, so a notice is held exactly when a re-run really is coming:
-
-    - exhausted ladder / disabled / paused / non-recurring → no re-run;
-    - the yield branch: when the schedule's own next occurrence lands at or before the
-      pending rung, ``plan_retry`` schedules nothing (the natural fire IS the retry).
-      Without this mirror, a job on a cadence at or under a rung held EVERY failure
-      notice for as long as the outage lasted: each failure yielded without consuming an
-      attempt, so the "once the ladder is exhausted, the next failure alerts normally"
-      escape in the suppression contract was unreachable and the operator saw silence.
-      (The final run of a finite repeat is a separate terminal-state edge handled by
-      #109991.)
-
-    Called before ``mark_job_run`` records the run; the occurrence is recomputed exactly
-    as ``_advance_after_run`` will (delivery-time skew between here and the store write
-    can only err toward delivering the notice, never toward suppressing it unheard).
-    """
+    """True iff ``plan_retry`` will park a re-run for this flagged failure, so the scheduler
+    may hold the interim notice: recurring, unpaused, ladder not exhausted, enabled, and the
+    rung strictly before the natural occurrence. Called before ``mark_job_run``."""
     if not _is_recurring(job) or job.get("state") == "paused":
         return False
     state = job.get(STATE_KEY) or {}

tests/cron/test_unreachable_retry.py

@@ -75,7 +75,7 @@ def test_unreachable_failure_pulls_next_run_earlier_then_ladder_exhausts(
     assert weekly["id"] not in {due["id"] for due in get_due_jobs()}
 
 
-def test_will_retry_mirrors_plan_retry_yield_and_terminal_paths(tmp_cron_home):
+def test_will_retry_mirrors_plan_retry_yield(tmp_cron_home):
     """The notice-suppression predictor must mirror what ``plan_retry`` will actually do
     for THIS failure: