tools(bootstrap_sanctoral): name.pl is optional, not required

lectio's regenerated tridentine-calendar.ini (the fix that corrects the
15-entry rank cluster and adds the 5 missing entries this branch
re-bootstraps from) has 5 entries with no name.pl field at all
(agnes-secundo, boniface-martyr, eusebius-confessor, evaristus, theodore --
all either newly added or newly un-hidden). parse_names previously required
name.pl unconditionally (`field sec "name.pl"`, which dies on absence) --
correct for a source that always had it, wrong now that it legitimately
does not.

Names.t is an open, per-language assoc list (names.mli) with no rule that
every entry must carry every language colitur happens to know about, so
requiring pl here was this tool's own invented constraint, not a kernel
one. Falls back to an en-only Names.t when pl is absent, never a
placeholder string.

1 files changed, 17 insertions, 2 deletions

diff --git a/tools/bootstrap_sanctoral.ml b/tools/bootstrap_sanctoral.ml
index 19adc0b..4135518 100644
--- a/tools/bootstrap_sanctoral.ml
+++ b/tools/bootstrap_sanctoral.ml
@@ -155,10 +155,25 @@ let parse_subject sec =
       | Some s -> s
       | None -> die "section [%s]: unknown class %S" sec.name raw)
 
+(* name.en is always required; name.pl is not -- the 2026-08-12 re-bootstrap
+   (RG16(a) blast-radius task) found 5 of the source's 322 entries missing it
+   outright (agnes-secundo, boniface-martyr, eusebius-confessor, evaristus,
+   theodore -- all 5 either newly added or newly un-hidden by lectio's own
+   generator fix, never previously reachable through this tool at all, since
+   every entry the OLD ini shipped happened to carry both languages). Prior
+   to this the field was unconditionally required (`field sec "name.pl"`,
+   which `die`s on absence) -- correct for a byte-faithful mirror of a
+   source that always had it, wrong once the source legitimately does not:
+   Names.t itself is an open, per-language assoc list (names.mli) with no
+   rule that every entry must carry every language colitur happens to know
+   about, so requiring pl here was this tool's own invented constraint, not
+   a kernel one. Falling back to en-only (never a placeholder string) is the
+   same posture the kernel takes elsewhere for a genuinely absent field. *)
 let parse_names sec =
   let en = field sec "name.en" in
-  let pl = field sec "name.pl" in
-  Names.of_list [ (Lang.of_string_exn "en", en); (Lang.of_string_exn "pl", pl) ]
+  match field_opt sec "name.pl" with
+  | Some pl -> Names.of_list [ (Lang.of_string_exn "en", en); (Lang.of_string_exn "pl", pl) ]
+  | None -> Names.of_list [ (Lang.of_string_exn "en", en) ]
 
 (* reading.* is deliberately ignored -- Plan 4's lectionary bootstrap. *)
 let convert_entry sec : V.rank Layer.entry =