chore: implement repo improvements plan (npm scripts, docs, catalog CI, i18n, validator)

- Add npm scripts: validate, validate:strict, index, readme, chain, catalog, build
- Align docs to V4 and 560 skills (GETTING_STARTED, FAQ, BUNDLES, MAINTENANCE, vietnamese)
- build-catalog: output to data/ for catalog, bundles, aliases; add to CI and drift check
- Add yaml dep, Node setup and catalog step in CI; extend auto-commit and drift msg
- Translate CI and MAINTENANCE to English; update CI_DRIFT_FIX and maintenance routine
- QUALITY_BAR/CONTRIBUTING: canonical validator npm run validate; legacy note in validate-skills.js

data/aliases.json

@@ -1,5 +1,5 @@
 {
-  "generatedAt": "2026-01-28T16:10:28.837Z",
+  "generatedAt": "2026-01-29T12:07:33.859Z",
   "aliases": {
     "accessibility-compliance-audit": "accessibility-compliance-accessibility-audit",
     "active directory attacks": "active-directory-attacks",

data/bundles.json

@@ -1,5 +1,5 @@
 {
-  "generatedAt": "2026-01-28T16:10:28.837Z",
+  "generatedAt": "2026-01-29T12:07:33.859Z",
   "bundles": {
     "core-dev": {
       "description": "Core development skills across languages, frameworks, and backend/frontend fundamentals.",

data/catalog.json

@@ -1,6 +1,6 @@
 {
-  "generatedAt": "2026-01-28T16:10:28.837Z",
-  "total": 552,
+  "generatedAt": "2026-01-29T12:07:33.859Z",
+  "total": 553,
   "skills": [
     {
       "id": "3d-web-experience",
@@ -12843,6 +12843,29 @@
       ],
       "path": "skills/unity-ecs-patterns/SKILL.md"
     },
+    {
+      "id": "unreal-engine-cpp-pro",
+      "name": "unreal-engine-cpp-pro",
+      "description": "Expert guide for Unreal Engine 5.x C++ development, covering UObject hygiene, performance patterns, and best practices.",
+      "category": "architecture",
+      "tags": [
+        "unreal",
+        "engine",
+        "cpp"
+      ],
+      "triggers": [
+        "unreal",
+        "engine",
+        "cpp",
+        "pro",
+        "development",
+        "covering",
+        "uobject",
+        "hygiene",
+        "performance"
+      ],
+      "path": "skills/unreal-engine-cpp-pro/SKILL.md"
+    },
     {
       "id": "upstash-qstash",
       "name": "upstash-qstash",