events: whole-series booking + 9 tests

ev/book-series! / ev/cancel-series! apply a booking/cancel to every occurrence
of one event in a window (RSVP the whole weekly class), returning per-
occurrence (occ-key status) results; capacity still enforced per occurrence
(some :booked, some :full), idempotent re-book (:already). ev/series-count,
ev/series-booked. 341/341 green.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

plans/events-on-sx.md

@@ -18,7 +18,7 @@ capacity rules, transactional booking, and a flow-driven notification dispatcher
 
 ## Status (rolling)
 
-`bash lib/events/conformance.sh` → **332/332** (Phases 1-4 + 11 ext: …e2e delivery, conflict-checked booking, iCalendar export)
+`bash lib/events/conformance.sh` → **341/341** (Phases 1-4 + 12 ext: …conflict-checked booking, iCalendar export, whole-series booking)
 
 ## Ground rules
 
@@ -88,6 +88,13 @@ lib/events/api.sx ── (events/schedule) (events/book) (events/agenda) ──
 
 ## Progress log
 
+- 2026-06-07 — Whole-series booking (extension). `ev/book-series!` /
+  `ev/cancel-series!` apply a booking/cancel to every occurrence of one event
+  in a window (e.g. RSVP the whole weekly class), returning per-occurrence
+  (occ-key status) results; capacity is still enforced per occurrence (some
+  :booked, some :full). Idempotent re-book (all :already). `ev/series-count`
+  (tally a status), `ev/series-booked` (which occurrences the actor holds).
+  +9 tests, 341/341 green. This was the last flagged feature — surface saturated.
 - 2026-06-07 — iCalendar (RFC 5545) export (extension). `ical.sx` serializes
   events to VEVENT / VCALENDAR text for import by standard clients. UTC
   basic-format stamps (YYYYMMDDTHHMM00Z), DURATION (PT#H#M), and the full RRULE