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

packages/agents-md-core/src/finder.ts

@@ -0,0 +1,20 @@
+import {
+  findAgentsMdUp as findAgentsMdUpCore,
+} from "@oh-my-opencode/rules-core";
+import { isAbsolute, resolve } from "node:path";
+
+import type { AgentsMdDiscoveryInput } from "./types";
+
+export function resolveFilePath(rootDirectory: string, path: string): string | null {
+  if (!path) return null;
+  if (isAbsolute(path)) return path;
+  return resolve(rootDirectory, path);
+}
+
+export async function findAgentsMdUp(input: AgentsMdDiscoveryInput): Promise<string[]> {
+  return findAgentsMdUpCore({
+    startDir: input.startDir,
+    rootDir: input.rootDir,
+    cache: input.cache,
+  });
+}