feat(events): the public calendar, event pages and participation history (Phase 14a)

The anonymous surface an event was always for: GET /public/events,
/public/events/:slug and /public/events/series/:slug, plus
GET /player/events/history, and the four screens over them.

Four org-lead decisions taken up front: split Phase 14 into 14a (website)
and 14b (the app); add a `listed` flag rather than letting `state` mean both
schedulable and announced; put the `events` capability string in the version
block rather than publishing core as a pseudo-module; and drop "venue" from
the spec rather than adding a field nothing had ever built.

`listed` is announcement, not permission. Publishing is what makes a
definition runnable, so without a separate flag a surprise event would have
to be advertised in order to be allowed to happen. It is a column, a switch
in Phase 13's editor, and three SQL predicates -- never a filter applied
after a read, which works exactly as well until the first caller that forgets.

The public shapes are a projection, and the projection is the security
boundary: nothing is spread, so a column added to event_runs next year does
not ride out through it. The spec, health, cleanup, claims, errors and
member_key are all absent by construction.

The six public event triggers gained `eventUrl` (version 1 -> 2), carrying
?run= because the page lives at the definition's slug while every trigger is
about one occurrence. notify.event-started gained the button, at seedVersion 2.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_016wDDVXWMDz82WqE1i969r4

client/test/apiClient.test.js

@@ -252,3 +252,40 @@ test('a Team slug is URL-encoded on every forum path', async () => {
   await api.teamForumReport('a b/c', { targetType: 'team_forum_thread', targetId: 1, reason: 'spam' })
   assert.equal(calls[0].url, '/api/v1/player/teams/a%20b%2Fc/forum/report')
 })
+
+
+// ── Public events (Phase 14a) ───────────────────────────────────────────
+//
+// The one shape worth pinning is `?run=`: it is what an announcement's link
+// carries, and a client that dropped it would make a mail about last Friday's
+// occurrence open next Friday's.
+
+test('the public calendar asks for no window at all by default', async () => {
+  willReply({ body: { entries: [] } })
+  await api.publicEvents()
+  // The server defaults to now through a month out, so the first render need
+  // not compute two ISO instants before it can ask for anything.
+  assert.equal(calls[0].url, '/api/v1/public/events')
+})
+
+test('an event page carries the run when one was named, and not when it was not', async () => {
+  willReply({ body: { ok: true } })
+  await api.publicEvent('the-yew-invasion')
+  assert.equal(calls[0].url, '/api/v1/public/events/the-yew-invasion')
+
+  willReply({ body: { ok: true } })
+  await api.publicEvent('the-yew-invasion', 3692)
+  assert.equal(calls[1].url, '/api/v1/public/events/the-yew-invasion?run=3692')
+})
+
+test('an event slug is URL-encoded on every public path', async () => {
+  willReply({ body: { ok: true } })
+  await api.publicEventSeries('a b/c')
+  assert.equal(calls[0].url, '/api/v1/public/events/series/a%20b%2Fc')
+})
+
+test('participation history takes a keyset cursor, never an offset', async () => {
+  willReply({ body: { entries: [] } })
+  await api.player.eventHistory({ limit: 25, before: 900 })
+  assert.equal(calls[0].url, '/api/v1/player/events/history?limit=25&before=900')
+})