Add shard activity feed + admin live feed; fix public-feed leak

Front ends for the rest of the sidecar data, plus a security fix the live data
surfaced.

- lib/shardEvents.js: shared describe()/category/label for every event kind
  (sales, deaths & PvP, skills, fame/karma, quests, world, and staff kinds).
- Public /site/shard/activity (ShardActivity): the full event log with category
  filter tabs and a live tail (history + SSE merged, de-duped). Linked from the
  Shard page. Shard page now reuses the shared describe().
- Admin: a "Live feed (all events)" panel on the Shard admin page subscribing to
  the admin SSE channel — shows every kind incl. audit/cheat/login attempts.
  useShardFeed generalized to take a stream url; api.adminShardStreamUrl added.

Security fix: GET /public/shard/feed now restricts to the public-safe kind
allowlist (shardEvents.list gains a `kinds` IN-filter). Previously it returned
whatever was logged — including audit.* / cheat.* / link.request. Those are
still stored for the admin channel but never served publicly (verified: a
public request for audit.command returns 0 rows).

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_011qPmpmVH1xGCiZoz9m9vW3

server/src/model/shardEvents/shardEvents.db.js

@@ -12,8 +12,18 @@ async function insertIgnore({ kind, t, bootId, payload, dedupeKey }) {
   return res.affectedRows > 0
 }
 
-// Recent events, newest first. Optional kind filter; limit is clamped by the model.
-async function list({ kind, limit }) {
+// Recent events, newest first. Filter by a single `kind`, or an allowlist of
+// `kinds` (IN clause) — the public feed uses the allowlist so it can never leak
+// staff/sensitive kinds. limit is clamped by the model.
+async function list({ kind, kinds, limit }) {
+  if (kinds && kinds.length) {
+    const placeholders = kinds.map(() => '?').join(', ')
+    return query(
+      `SELECT id, kind, t, boot_id, payload, created_at
+         FROM shard_events WHERE kind IN (${placeholders}) ORDER BY t DESC LIMIT ?`,
+      [...kinds, limit],
+    )
+  }
   if (kind) {
     return query(
       `SELECT id, kind, t, boot_id, payload, created_at