fix(lint): exempt meta-skills from lineage/source checks

The compare-masters skill is an aggregate meta-skill that borrows from
other masters and has no single lineage, dates, sources, or own corpus
directories. Treating it as a regular master made --strict CI fail on
all branches since 2026-04-08.

Introduce a kind field (default master) and skip the lineage/dates/
sources/citation_format and references/sources directory checks when
kind == meta-skill. compare/SKILL.md gains kind: meta-skill.

Required fields (name, description) and version/license are still
enforced for all skills.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

prebuilt/compare/SKILL.md

@@ -3,6 +3,7 @@ name: compare-masters
 description: Use when user asks to compare masters, compare schools, compare perspectives, 对比, 各宗怎么看, 不同宗派, 禅净之争, 性相之辩, 空有之争, or wants multiple masters to answer the same question. Triggers include "对比"、"比较"、"各宗"、"不同宗派怎么看"、"禅宗和净土"、"天台和华严"、"唯识和中观"、"空有之争"、"性相之辩"、"各位祖师"、"多个角度"、"compare"、"comparison" — invoke whenever user's question implicitly or explicitly seeks multi-tradition perspectives on a Buddhist topic.
 version: 0.3.0
 license: MIT
+kind: meta-skill
 verified_by: xr843
 verified_at: 2026-04-06
 ---

scripts/validate.py

@@ -24,6 +24,8 @@ PREBUILT_DIR = Path(__file__).resolve().parent.parent / "prebuilt"
 
 REQUIRED_FIELDS = {"name", "description"}
 RECOMMENDED_FIELDS = {"version", "license", "lineage", "dates", "sources", "citation_format"}
+# Fields not applicable to meta-skills (aggregate/comparison skills with no single lineage)
+META_SKILL_EXCLUDED = {"lineage", "dates", "sources", "citation_format"}
 MAX_DESCRIPTION_CHARS = 500
 MAX_SKILL_LINES = 500
 
@@ -104,7 +106,10 @@ def lint_master(master_dir: Path, strict: bool = False) -> list[str]:
             issues.append(f"[ERROR] {name}: missing required field '{field}'")
 
     # --- Recommended fields ---
+    kind = fm.get("kind", "master")
     for field in RECOMMENDED_FIELDS:
+        if kind == "meta-skill" and field in META_SKILL_EXCLUDED:
+            continue
         if field not in fm:
             issues.append(f"[WARN]  {name}: missing recommended field '{field}'")
 
@@ -126,6 +131,8 @@ def lint_master(master_dir: Path, strict: bool = False) -> list[str]:
                     issues.append(f"[WARN]  {name}: sources[{i}] missing 'title' or 'cbeta_id'")
 
     # --- Directory structure checks ---
+    # Meta-skills (e.g. compare-masters) borrow from other masters and have no own corpus
+    if kind != "meta-skill":
         refs_dir = master_dir / "references"
         sources_dir = master_dir / "sources"