feat(skills): add cleanup-artifacts skill and session hygiene protocol

bin/sync-skills

@@ -8,11 +8,17 @@ import sys
 
 
 def lexical(path):
-    return Path(os.path.abspath(path))
+    s = str(os.path.abspath(path))
+    if s.startswith('\\\\?\\'):
+        s = s[4:]
+    return Path(s)
 
 
 def link_target(path):
-    return lexical(path.parent / os.readlink(path))
+    target = os.readlink(path)
+    if os.path.isabs(target):
+        return lexical(target)
+    return lexical(path.parent / target)
 
 
 def inside(path, root):

bin/validate-skills

@@ -51,7 +51,7 @@ def metadata(text):
 
 def local_links(path):
     fenced = False
-    for number, line in enumerate(path.read_text().splitlines(), 1):
+    for number, line in enumerate(path.read_text(encoding='utf-8').splitlines(), 1):
         if line.lstrip().startswith(('```', '~~~')):
             fenced = not fenced
             continue