refactor(slack): share room context hints

src/slack/monitor/room-context.ts

@@ -0,0 +1,31 @@
+import { buildUntrustedChannelMetadata } from "../../security/channel-metadata.js";
+
+export function resolveSlackRoomContextHints(params: {
+  isRoomish: boolean;
+  channelInfo?: { topic?: string; purpose?: string };
+  channelConfig?: { systemPrompt?: string | null } | null;
+}): {
+  untrustedChannelMetadata?: ReturnType<typeof buildUntrustedChannelMetadata>;
+  groupSystemPrompt?: string;
+} {
+  if (!params.isRoomish) {
+    return {};
+  }
+
+  const untrustedChannelMetadata = buildUntrustedChannelMetadata({
+    source: "slack",
+    label: "Slack channel description",
+    entries: [params.channelInfo?.topic, params.channelInfo?.purpose],
+  });
+
+  const systemPromptParts = [params.channelConfig?.systemPrompt?.trim() || null].filter(
+    (entry): entry is string => Boolean(entry),
+  );
+  const groupSystemPrompt =
+    systemPromptParts.length > 0 ? systemPromptParts.join("\n\n") : undefined;
+
+  return {
+    untrustedChannelMetadata,
+    groupSystemPrompt,
+  };
+}