fix(skills): frontmatter lint — using-interns v0.3.1 (YAML+≤1024), using-wiki-graph v0.1.1 (≤1024), ralph-loop-execution frontmatter, remove using-yt-tools stub, add scripts/lint-skills.py + wire into update.{sh,ps1}

scripts/lint-skills.py

@@ -0,0 +1,85 @@
+#!/usr/bin/env python3
+"""lint-skills.py — Agent Skills spec lint over a skills catalog.
+
+Checks every SKILL.md:
+  1. frontmatter parses as YAML
+  2. `description` present and <= 1024 chars (spec cap)
+  3. required fields present: name, description (version optional-but-encouraged)
+
+Exit code 0 = clean, 1 = violations found (prints them).
+Usage:  python lint-skills.py [skills-dir]   (default: ./skills)
+"""
+import os
+import sys
+
+try:
+    import yaml
+except ImportError:
+    print("error: PyYAML required (pip install pyyaml)", file=sys.stderr)
+    sys.exit(2)
+
+MAX_DESC = 1024
+REQUIRED = ("name", "description")
+
+
+def lint_one(path):
+    """Return list of violation strings for one SKILL.md."""
+    problems = []
+    txt = open(path, encoding="utf-8").read()
+    if not txt.startswith("---"):
+        return [f"{path}: missing frontmatter (must start with ---)"]
+    try:
+        fm = txt.split("---", 2)[1]
+        d = yaml.safe_load(fm)
+    except Exception as e:
+        return [f"{path}: frontmatter YAML parse error: {str(e)[:80]}"]
+    if not isinstance(d, dict):
+        return [f"{path}: frontmatter is not a mapping"]
+    for f in REQUIRED:
+        if not d.get(f):
+            problems.append(f"{path}: missing required field '{f}'")
+    desc = d.get("description") or ""
+    if len(desc) > MAX_DESC:
+        problems.append(f"{path}: description exceeds {MAX_DESC} chars ({len(desc)})")
+    return problems
+
+
+def warn_one(path):
+    """Soft findings (not spec violations)."""
+    warnings = []
+    txt = open(path, encoding="utf-8").read()
+    if not txt.startswith("---"):
+        return warnings
+    d = yaml.safe_load(txt.split("---", 2)[1])
+    if isinstance(d, dict) and not d.get("version"):
+        warnings.append(f"{path}: missing version (encouraged)")
+    return warnings
+
+
+def main():
+    root = sys.argv[1] if len(sys.argv) > 1 else "skills"
+    if not os.path.isdir(root):
+        print(f"error: not a directory: {root}", file=sys.stderr)
+        return 2
+    all_problems = []
+    all_warnings = []
+    count = 0
+    for dirpath, dirnames, filenames in os.walk(root):
+        if "SKILL.md" in filenames:
+            count += 1
+            p = os.path.join(dirpath, "SKILL.md")
+            all_problems.extend(lint_one(p))
+            all_warnings.extend(warn_one(p))
+    for w in all_warnings:
+        print("  W: " + w)
+    if all_problems:
+        print(f"lint: {count} skills, {len(all_problems)} violations:")
+        for p in all_problems:
+            print("  " + p)
+        return 1
+    print(f"lint: {count} skills, 0 violations ({len(all_warnings)} warnings)")
+    return 0
+
+
+if __name__ == "__main__":
+    sys.exit(main())

scripts/update.ps1

@@ -133,6 +133,10 @@ if (Test-Path (Join-Path $internsMcp '.git')) {
 
 Pop-Location
 Write-Host "[update] Installing skills..." -ForegroundColor Cyan
+# 0. Lint skills against Agent Skills spec (fail on violations)
+& python "$root\scripts\lint-skills.py" "$root\skills" 2>$null
+if ($LASTEXITCODE -ne 0) { Write-Host "[update] SKILL.md lint failed - fix before install" -ForegroundColor Red; exit 1 }
+# 1. Install all skills via install.ps1
 & "$root\scripts\install.ps1"
 Write-Host "[ok] Skills installed." -ForegroundColor Green
 

scripts/update.sh

@@ -123,7 +123,10 @@ fi
 
 cd "$ROOT"
 info "Installing skills..."
-bash "$ROOT/scripts/install.sh"
+  # 0. Lint skills against Agent Skills spec (fail on violations)
+  python "$ROOT/scripts/lint-skills.py" "$ROOT/skills" || { error "SKILL.md lint failed - fix before install"; exit 1; }
+  # 1. Install all skills via install.sh
+  bash "$ROOT/scripts/install.sh"
 ok "Skills installed."
 
 # ── Step 5: Version diff ───────────────────────────────────────────────────