refactor(packages): rename rules-core to rules-engine

Ultraworked with [Sisyphus](https://github.com/code-yeongyu/oh-my-openagent)

Co-authored-by: Sisyphus <clio-agent@sisyphuslabs.ai>

packages/rules-engine/src/ordering.ts

@@ -0,0 +1,26 @@
+import { SOURCE_PRIORITY } from "./constants";
+import type { RuleFileCandidate } from "./types";
+
+export function sortCandidates<T extends RuleFileCandidate>(candidates: readonly T[]): T[] {
+  return candidates
+    .map((candidate, index) => ({ candidate, index }))
+    .sort((left, right) => compareCandidates(left.candidate, right.candidate) || left.index - right.index)
+    .map(({ candidate }) => candidate);
+}
+
+function compareCandidates(left: RuleFileCandidate, right: RuleFileCandidate): number {
+  return (
+    Number(left.isGlobal) - Number(right.isGlobal) ||
+    left.distance - right.distance ||
+    (SOURCE_PRIORITY.get(left.source) ?? Number.POSITIVE_INFINITY) -
+      (SOURCE_PRIORITY.get(right.source) ?? Number.POSITIVE_INFINITY) ||
+    compareString(left.relativePath, right.relativePath) ||
+    compareString(left.realPath, right.realPath)
+  );
+}
+
+function compareString(left: string, right: string): number {
+  if (left < right) return -1;
+  if (left > right) return 1;
+  return 0;
+}