feat: deepen skill test coverage — 52 → 247 cases across all 43 skills

Add 195 new test cases covering examples from SKILL.md, edge cases,
and parameter combinations. Create _skill.json for form-edit, skd-edit,
subsystem-edit. Add fixtures for negative validate cases. Fix
normalizeUuids in meta-validate/meta-info configs.

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

tests/skills/cases/subsystem-edit/_skill.json

@@ -0,0 +1,13 @@
+{
+  "script": "subsystem-edit/scripts/subsystem-edit",
+  "setup": "empty-config",
+  "args": [
+    { "flag": "-SubsystemPath", "from": "workPath", "field": "subsystemPath" },
+    { "flag": "-DefinitionFile", "from": "inputFile" },
+    { "flag": "-NoValidate", "from": "switch" }
+  ],
+  "snapshot": {
+    "root": "workDir",
+    "normalizeUuids": true
+  }
+}