feat(events): enablement, per-run caps and mayInvoke (Phase 6)

Two new tables — event_action_settings (the deployment switchboard) and
event_run_budget (what a run has spent and the most it may) — plus verified_at
and verified_by on event_versions. The whole authorisation decision moves behind
one function, events/authorize.js: role, enablement, cap, and the shard's own
switch named as the layer core deliberately does not duplicate.

Three routes, none moved: GET/PUT /admin/events/actions (admin in both
directions) and POST /admin/events/:id/verify (admin, editor — a dry run
dispatches nothing).

Four decisions, settled by the org lead 2026-09-03:

- The default-off line falls between inspect and change, not between notify and
  inspect. Read literally, §K shipped core.wait disabled. The same line is the
  role floor.
- The tightest cap wins where two actions spend one dimension, pinned into the
  run at creation with the action it came from.
- A refusal follows the step's on_failure and takes health to degraded — its own
  status and its own log kind, because a refusal is not an outage.
- The verify gate is enforced for scheduled starts only: a human pressing Start
  now is the review the gate exists to require.

Derived and flagged for review: a dry run fails rather than warns on a disabled
action or an over-cap plan, and the unattended path does not re-check the
starter's role.

+111 tests (1921/1847/73/1 — the one failure pre-existing and environmental),
including a 403 walk over the real router and two concurrent spends against one
cap on a real MariaDB. The live walk found two defects, both fixed here: the run
console route dropped the budget it was handed, and the role refusal used a
plural verb over a one-item list.

Co-Authored-By: Claude <noreply@anthropic.com>
Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01T6t8mrAWhZU5vnyYgZTMtL

server/src/model/events/eventVersions.db.js

@@ -51,4 +51,24 @@ const insert = async (definitionId, version, spec, userId) => {
   return result.insertId
 }
 
-module.exports = { listForDefinition, getById, nextVersion, insert }
+/**
+ * Record that a dry run passed against this version (Phase 6).
+ *
+ * A version is immutable in every respect that describes the EVENT — its spec,
+ * its number, who published it. These two columns describe something that
+ * happened to it afterwards, which is why they can be written at all: a pass is
+ * a fact about a review, not a change to the plan reviewed.
+ *
+ * Deliberately not idempotent-checked: verifying twice stamps the second one, and
+ * the later reviewer is the more useful answer to "who last looked at this
+ * before it ran unattended".
+ */
+const markVerified = async (id, userId, at = new Date()) => {
+  const result = await query(
+    'UPDATE event_versions SET verified_at = ?, verified_by = ? WHERE id = ?',
+    [at, userId, id],
+  )
+  return (result.affectedRows || 0) > 0
+}
+
+module.exports = { listForDefinition, getById, nextVersion, insert, markVerified }