fix(api): belief events were published before their transaction committed

The API's belief emitter published every event as soon as it was appended.
Belief retraction runs inside its own transaction, so subscribers on the
event bus saw belief_retracted while the belief row still held its old
status, breaking the rule that subscribers never see uncommitted events;
a plan reacting to a retracted assumption read the belief before the
change and did nothing. The emitter now only appends, and every API and UI
caller publishes the operation's events after it succeeds.

internal/ui/memory.go

@@ -122,7 +122,9 @@ func (u *UI) memoryRetract(w http.ResponseWriter, r *http.Request) {
 	u.deps.Audit.Log(r.Context(), "memory.retract", "memory", id.String(), map[string]any{"reason": reason})
 	if affected, err := u.deps.Beliefs.RetractEvidence(r.Context(), u.deps.DB, m.ID, "memory", string(id)); err == nil {
 		for _, bid := range affected {
-			u.deps.Beliefs.Reevaluate(r.Context(), u.deps.DB, u.emitF(), m.ID, bid, "supporting memory retracted by operator") //nolint:errcheck
+			if res, err := u.deps.Beliefs.Reevaluate(r.Context(), u.deps.DB, u.emitF(), m.ID, bid, "supporting memory retracted by operator"); err == nil {
+				u.deps.Events.Publish(res.Events...)
+			}
 		}
 	}
 	u.flash(w, r, "ok", "Memory marked inaccurate. It remains in history.", "/minds/"+m.Slug+"/memory/"+id.String())