events: api.sx — public events facade + 14 tests (Phase 1 complete)

Immutable store ({:events :bookings}) over calendar+availability:
ev/schedule, ev/book, ev/agenda, ev/agenda-for, ev/free?, ev/next-free,
ev/conflicts. Availability queries auto-widen expansion by longest event.
73/73 green. Phase 1 done.

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` → **59/59** (Phase 1: calendar + availability)
+`bash lib/events/conformance.sh` → **73/73** (Phase 1 complete: calendar + availability + api)
 
 ## Ground rules
 
@@ -58,8 +58,8 @@ lib/events/api.sx ── (events/schedule) (events/book) (events/agenda) ──
 - [x] `calendar.sx` — MONTHLY (bymonthday + nth-weekday byday)
 - [x] `availability.sx` — free/busy rules (busy/conflict/busy_in on Datalog)
 - [x] `availability.sx` — next-free slot search (same rules, different bindings)
-- [ ] `api.sx` — public entry points (schedule/agenda/free-check)
-- [ ] tests + scoreboard + conformance.sh [done incrementally; api.sx pending]
+- [x] `api.sx` — public entry points (schedule/agenda/book/free/next-free/conflicts)
+- [x] tests + scoreboard + conformance.sh (73/73)
 
 ## Phase 2 — Ticketing + booking
 - [ ] capacity rules; transactional booking → `persist` (no overbooking)
@@ -79,6 +79,13 @@ lib/events/api.sx ── (events/schedule) (events/book) (events/agenda) ──
 
 ## Progress log
 
+- 2026-06-07 — **Phase 1 complete.** `api.sx`: immutable `store`
+  ({:events :bookings}) facade over calendar + availability. `ev/schedule`,
+  `ev/book`, `ev/agenda`, `ev/agenda-for`, `ev/free?`, `ev/next-free`,
+  `ev/conflicts`. Availability queries auto-widen the expansion window back by
+  the longest event so any overlapping occurrence is captured. 14 tests,
+  73/73 green. Phase 2 (transactional booking on persist) is next — `ev/book`
+  becomes capacity-safe via a persist append at that point.
 - 2026-06-07 — `next-free` slot search: earliest start ≥ after where
   [s,s+duration) is free and ends ≤ horizon, else nil. Candidates are `after`
   plus each busy-interval end (interval-packing); each probe reuses the