merge: custom skill sources

# Conflicts:
#	skiff/README.md
#	skiff/cli.py
#	skiff/project.py

skiff/skills.py

@@ -7,6 +7,7 @@ from pathlib import Path
 
 from skiff.paths import SKILLS_DIR, TEMPLATE_DIR, ensure_skills_home
 from skiff.registry import external_skill_path, load_registry
+from skiff.sources import list_source_skills, load_sources, source_skills_root
 
 
 def list_owned_skills() -> list[str]:
@@ -31,26 +32,81 @@ def owned_skill_path(name: str) -> Path:
     return path
 
 
+def split_skill_spec(spec: str, source: str | None = None) -> tuple[str, str | None]:
+    if "/" not in spec:
+        return spec, source
+    qualified_source, name = spec.split("/", 1)
+    if not qualified_source or not name or "/" in name:
+        raise SystemExit(f"skill 限定名称无效: {spec!r}（应为 source/name）")
+    if source and source != qualified_source:
+        raise SystemExit(
+            f"skill 来源冲突: {spec!r} 与 --source {source!r} 不一致"
+        )
+    return name, qualified_source
+
+
+def list_custom_skills(source: str | None = None) -> dict[str, list[str]]:
+    sources = load_sources()
+    if source:
+        if source not in sources:
+            raise SystemExit(f"未配置 source: {source}")
+        return {source: list_source_skills(source, sources[source])}
+    return {name: list_source_skills(name, entry) for name, entry in sources.items()}
+
+
 def resolve_skill_source(name: str, *, source: str | None = None) -> tuple[Path, str]:
-    """返回 (skill_path, kind)，kind 为 owned 或 external。"""
+    """返回 (skill_path, source)，未指定来源时拒绝同名歧义。"""
     ensure_skills_home()
+    name, source = split_skill_spec(name, source)
 
     owned = SKILLS_DIR / name
-    if source in (None, "owned") and (owned / "SKILL.md").is_file():
+    if source == "owned":
+        if not (owned / "SKILL.md").is_file():
+            raise SystemExit(f"owned source 中找不到 skill: {name}")
         return owned, "owned"
 
     registry = load_registry()
-    if source in (None, "registry") and name in registry:
+    if source == "registry":
+        if name not in registry:
+            raise SystemExit(f"registry 中找不到 skill: {name}")
         path = external_skill_path(name, registry[name])
         if not (path / "SKILL.md").is_file():
             raise SystemExit(
                 f"外部 skill {name!r} 尚未 fetch 或 path 中缺少 SKILL.md。"
                 f"请运行: skiff fetch {name}"
             )
-        return path, "external"
+        return path, "registry"
 
+    sources = load_sources()
+    if source:
+        if source not in sources:
+            raise SystemExit(
+                f"项目依赖 source {source!r}，但本机尚未配置。"
+                f"请运行: skiff source add {source} <repo>"
+            )
+        path = source_skills_root(source, sources[source]) / name
+        if not (path / "SKILL.md").is_file():
+            raise SystemExit(f"source {source!r} 中找不到 skill: {name}")
+        return path, source
+
+    candidates: list[tuple[Path, str]] = []
     if (owned / "SKILL.md").is_file():
-        return owned, "owned"
+        candidates.append((owned, "owned"))
+    if name in registry:
+        candidates.append((external_skill_path(name, registry[name]), "registry"))
+    for source_name, entry in sources.items():
+        path = source_skills_root(source_name, entry) / name
+        if (path / "SKILL.md").is_file():
+            candidates.append((path, source_name))
+
+    if len(candidates) > 1:
+        choices = ", ".join(f"{candidate_source}/{name}" for _, candidate_source in candidates)
+        raise SystemExit(f"skill 名称存在多个来源，请明确指定: {choices}")
+    if candidates:
+        path, resolved_source = candidates[0]
+        if resolved_source == "registry" and not path.exists():
+            raise SystemExit(f"外部 skill {name!r} 尚未 fetch。请先运行: skiff fetch {name}")
+        return path, resolved_source
 
     raise SystemExit(f"找不到 skill: {name}")