addInlineSlot method
Stores the resolved config and its trigger payload for slotKey. The
payload's cepCampaignId is what removeInlineSlotByCampaignId matches on,
so no separate id map is needed.
Implementation
void addInlineSlot(
String slotKey,
CampaignConfigModel config,
CEPTriggerPayload payload,
) {
_slotConfigs[slotKey] = config;
_slotPayloads[slotKey] = payload;
notifyListeners();
}