refactor(packages): extract agents-md-core package

packages/agents-md-core/src/injection-cache.ts

@@ -0,0 +1,14 @@
+import type { AgentsMdInjectedPathsStorage } from "./types";
+
+export function getSessionCache(input: {
+  readonly sessionCaches: Map<string, Set<string>>;
+  readonly sessionID: string;
+  readonly storage: Pick<AgentsMdInjectedPathsStorage, "loadInjectedPaths">;
+}): Set<string> {
+  const existing = input.sessionCaches.get(input.sessionID);
+  if (existing) return existing;
+
+  const loaded = input.storage.loadInjectedPaths(input.sessionID);
+  input.sessionCaches.set(input.sessionID, loaded);
+  return loaded;
+}