feat: 迁移统一目录元数据契约 (#102)

## 中文

- 为 System Agent、34 个 Builtin Skill、28 个 Pointer/Collection 条目增加 catalog
sidecar
- 覆盖 147 个 collection child，并固定可证明的来源；无法证明的内容保持 listing-only/unknown
- 增加 strict Schema、validator、collection check 与 CI 完整性门禁

## English

- Add catalog metadata sidecars for the System Agent, 34 built-in
Skills, and 28 pointer/collection entries
- Cover 147 collection children while keeping unverifiable facts
listing-only or unknown
- Add strict schemas, validators, deterministic collection checks, and
CI completeness gates

## 验证 / Verification

- Catalog validator 17/17
- Collection generator 4/4
- 63 sidecars, 147 children, zero errors

skills/clone-agent/catalog-metadata.v1.json

@@ -0,0 +1,73 @@
+{
+  "$schema": "../../schemas/catalog-metadata.v1.schema.json",
+  "schemaVersion": 1,
+  "identity": {
+    "kind": "skill",
+    "id": "clone-agent"
+  },
+  "presentation": {
+    "defaultLocale": "en-US",
+    "i18n": {
+      "zh-CN": {
+        "name": "克隆智能体",
+        "summary": "完整复制现有智能体为独立本地副本，可选继承用户私有数据",
+        "description": "完整克隆现有智能体为独立本地副本，并安全处理私有记忆、偏好、关系与团队分发影响。Use when 用户要求复制、克隆或基于现有 Agent 创建独立变体。"
+      },
+      "en-US": {
+        "name": "Clone Agent",
+        "summary": "Clone an existing Agent into an independent local copy with optional private user data",
+        "description": "Clone an existing Agent into an independent local copy while safely handling private memory, preferences, relationships, and team distribution impact. Use when the user asks to copy, clone, or create an independent variant from an existing Agent."
+      }
+    },
+    "category": "productivity",
+    "tags": [
+      "agent",
+      "clone",
+      "meta"
+    ]
+  },
+  "release": {
+    "state": "known",
+    "version": "1.0.1",
+    "versionScheme": "semver"
+  },
+  "timestamps": {
+    "catalogUpdatedAt": {
+      "state": "known",
+      "value": "2026-08-25T09:25:42Z",
+      "precision": "second"
+    },
+    "releasePublishedAt": {
+      "state": "unknown"
+    },
+    "reviewedAt": {
+      "state": "unknown"
+    },
+    "upstreamObservedAt": {
+      "state": "unknown"
+    }
+  },
+  "provenance": {},
+  "governance": {
+    "stewardship": "official",
+    "availability": "installable",
+    "license": {
+      "state": "unknown"
+    },
+    "redistribution": "verify-package-terms",
+    "listingMaintainer": {
+      "name": "DesireCore Official",
+      "verified": true
+    }
+  },
+  "compatibility": {
+    "platforms": {
+      "state": "unknown"
+    },
+    "requiredClientVersion": "10.0.115"
+  },
+  "spec": {
+    "kind": "skill",
+    "riskLevel": "medium"
+  }
+}