events: RRULE EXDATE/RDATE exceptions + 8 tests

ev-event-full carries :exdate/:rdate. ev-expand-base = raw expansion;
ev-expand applies exceptions: RDATE adds in-window occurrences, EXDATE removes
matching starts, de-duped, EXDATE wins over RDATE and the rrule (RFC 5545).
RDATE-only events supported; plain ev-event unaffected. 248/248 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` → **240/240** (Phases 1-4 + ext: federated free/busy, waitlist)
+`bash lib/events/conformance.sh` → **248/248** (Phases 1-4 + ext: fed free/busy, waitlist, EXDATE/RDATE)
 
 ## Ground rules
 
@@ -86,6 +86,13 @@ lib/events/api.sx ── (events/schedule) (events/book) (events/agenda) ──
 
 ## Progress log
 
+- 2026-06-07 — RRULE exceptions EXDATE/RDATE (extension). `ev-event-full`
+  carries :exdate/:rdate (epoch-minute starts). Raw expansion renamed
+  `ev-expand-base`; `ev-expand` now applies exceptions: RDATE adds explicit
+  in-window occurrences, EXDATE removes matching starts, duplicates de-duped,
+  EXDATE wins over RDATE and the rrule (RFC 5545). RDATE-only events (no rrule)
+  supported. Plain `ev-event` (no exception keys) unaffected. +8 tests,
+  248/248 green.
 - 2026-06-07 — Waitlist + auto-promotion (extension). When an occurrence is
   full, `ev/waitlist!` queues actors FIFO (:waitlist/:unwaitlist events on the
   same stream; waiting fold is independent of the seat fold since taking a seat