feat: add skill regression test runner with meta-compile pilot

Snapshot-based test runner (tests/skills/runner.mjs) for verifying
skill script output. Zero dependencies, runs on any machine with
Node.js — no 1C platform needed for daily regression.

Pilot: meta-compile with 6 cases (4 positive with snapshots, 2 negative).

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

tests/skills/cases/meta-compile/catalog-basic.json

@@ -0,0 +1,7 @@
+{
+  "name": "Простой справочник без реквизитов",
+  "input": { "type": "Catalog", "name": "Валюты" },
+  "expect": {
+    "files": ["Catalogs/Валюты.xml", "Catalogs/Валюты/Ext/ObjectModule.bsl"]
+  }
+}