Add drawio-main skill (renamed from drawio-main-v1)

Draw.io diagram generation and analysis skill: mandatory layout and
style rules, XML reference, negative-space companion diagrams, and
the drawio-tools TypeScript CLI with 12 analysis/validation actions.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

package.json

@@ -0,0 +1,28 @@
+{
+  "name": "drawio-tools",
+  "version": "0.1.0",
+  "description": "CLI tools for draw.io diagram analysis and verification",
+  "type": "module",
+  "packageManager": "pnpm@11.9.0",
+  "bin": {
+    "drawio-tools": "dist/cli/commands.js"
+  },
+  "scripts": {
+    "build": "tsc",
+    "cli": "tsc && node dist/cli/commands.js"
+  },
+  "dependencies": {
+    "@maxgraph/core": "^0.23.0",
+    "js-yaml": "^4.1.0",
+    "jsdom": "^25.0.0",
+    "pako": "^2.1.0"
+  },
+  "devDependencies": {
+    "@types/js-yaml": "^4.0.9",
+    "@types/jsdom": "^21.1.7",
+    "@types/node": "^22.0.0",
+    "@types/pako": "^2.0.3",
+    "tsx": "^4.19.0",
+    "typescript": "^5.7.0"
+  }
+}