fix: refactor update_readme to match current README (counts only, no Full Skill Registry)

- Remove Full Skill Registry and table logic; keep only count substitutions
- Add Browse N+ Skills and TOC link updates
- Always write README after substitutions so chain completes without error

data/aliases.json

@@ -1,5 +1,5 @@
 {
-  "generatedAt": "2026-01-29T12:07:33.859Z",
+  "generatedAt": "2026-01-29T12:12:48.100Z",
   "aliases": {
     "accessibility-compliance-audit": "accessibility-compliance-accessibility-audit",
     "active directory attacks": "active-directory-attacks",

data/bundles.json

@@ -1,5 +1,5 @@
 {
-  "generatedAt": "2026-01-29T12:07:33.859Z",
+  "generatedAt": "2026-01-29T12:12:48.100Z",
   "bundles": {
     "core-dev": {
       "description": "Core development skills across languages, frameworks, and backend/frontend fundamentals.",

data/catalog.json

@@ -1,5 +1,5 @@
 {
-  "generatedAt": "2026-01-29T12:07:33.859Z",
+  "generatedAt": "2026-01-29T12:12:48.100Z",
   "total": 553,
   "skills": [
     {