refactor: centralize outbound policy + target schema

src/infra/outbound/channel-adapters.ts

@@ -0,0 +1,24 @@
+import type { ChannelId } from "../../channels/plugins/types.js";
+
+export type ChannelMessageAdapter = {
+  supportsEmbeds: boolean;
+  buildCrossContextEmbeds?: (originLabel: string) => unknown[];
+};
+
+const DEFAULT_ADAPTER: ChannelMessageAdapter = {
+  supportsEmbeds: false,
+};
+
+const DISCORD_ADAPTER: ChannelMessageAdapter = {
+  supportsEmbeds: true,
+  buildCrossContextEmbeds: (originLabel: string) => [
+    {
+      description: `From ${originLabel}`,
+    },
+  ],
+};
+
+export function getChannelMessageAdapter(channel: ChannelId): ChannelMessageAdapter {
+  if (channel === "discord") return DISCORD_ADAPTER;
+  return DEFAULT_ADAPTER;
+}