feat: add meta-validate, meta-info tests and broken fixtures

- meta-validate: 3 cases (valid catalog, bad root element, file not found)
- meta-info: 2 cases (catalog overview with stdoutContains, not found error)
- fixtures/broken/catalog-bad-root for negative validate tests
- All 5 skill archetypes now covered: compile, init, edit, validate, info

17 tests, all passing.

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

tests/skills/cases/meta-validate/valid-catalog.json

@@ -0,0 +1,12 @@
+{
+  "name": "Корректный справочник проходит валидацию",
+  "setup": "empty-config",
+  "preRun": [
+    {
+      "script": "meta-compile/scripts/meta-compile",
+      "input": { "type": "Catalog", "name": "Тест" },
+      "args": { "-JsonPath": "{inputFile}", "-OutputDir": "{workDir}" }
+    }
+  ],
+  "params": { "objectPath": "Catalogs/Тест" }
+}