feat: add form-*, skd-*, misc tests (batches 1, 2, 10)

New skills covered:
- form-add, form-compile, form-validate, form-info (batch 1)
- skd-compile, skd-validate, skd-info (batch 2)
- help-add, template-add, template-remove, meta-remove (batch 10)

Findings: form-add/form-info path resolution inconsistency,
meta-remove self-reference requires -Force.

45 tests across 33 skills, all passing.

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

tests/skills/cases/skd-info/_skill.json

@@ -0,0 +1,11 @@
+{
+  "script": "skd-info/scripts/skd-info",
+  "setup": "none",
+  "args": [
+    { "flag": "-TemplatePath", "from": "workPath", "field": "templatePath" }
+  ],
+  "snapshot": {
+    "root": "workDir",
+    "normalizeUuids": true
+  }
+}