feat: update clean-code skill and stabilize registry (#69)

- Updated clean-code skill with Robert C. Martin's Clean Code principles
- Refined content: naming, functions, comments, error handling, class design
- Fixed invalid heading format (## ## When to Use -> ## When to Use)
- Stabilized registry: use SOURCE_DATE_EPOCH for deterministic CI builds
- Improved catalog sorting for cross-environment consistency
- Regenerated all catalog and index files

Co-authored-by: jackjin1997 <jackjin1997@users.noreply.github.com>

data/aliases.json

@@ -1,5 +1,5 @@
 {
-  "generatedAt": "2026-02-06T08:53:44.091Z",
+  "generatedAt": "2026-02-08T10:01:43.886Z",
   "aliases": {
     "accessibility-compliance-audit": "accessibility-compliance-accessibility-audit",
     "active directory attacks": "active-directory-attacks",

data/bundles.json

@@ -1,5 +1,5 @@
 {
-  "generatedAt": "2026-02-06T08:53:44.091Z",
+  "generatedAt": "2026-02-08T10:01:43.886Z",
   "bundles": {
     "core-dev": {
       "description": "Core development skills across languages, frameworks, and backend/frontend fundamentals.",

data/catalog.json

@@ -1,5 +1,5 @@
 {
-  "generatedAt": "2026-02-06T08:53:44.091Z",
+  "generatedAt": "2026-02-08T10:01:43.886Z",
   "total": 713,
   "skills": [
     {
@@ -2969,7 +2969,7 @@
     {
       "id": "clean-code",
       "name": "clean-code",
-      "description": "Pragmatic coding standards - concise, direct, no over-engineering, no unnecessary comments",
+      "description": "Applies principles from Robert C. Martin's 'Clean Code'. Use this skill when writing, reviewing, or refactoring code to ensure high quality, readability, and maintainability. Covers naming, functions, comments, error handling, and class design.",
       "category": "general",
       "tags": [
         "clean",
@@ -2978,15 +2978,16 @@
       "triggers": [
         "clean",
         "code",
-        "pragmatic",
-        "coding",
-        "standards",
-        "concise",
-        "direct",
-        "no",
-        "engineering",
-        "unnecessary",
-        "comments"
+        "applies",
+        "principles",
+        "robert",
+        "martin",
+        "skill",
+        "writing",
+        "reviewing",
+        "refactoring",
+        "high",
+        "quality"
       ],
       "path": "skills/clean-code/SKILL.md"
     },