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/python-runtime/catalog-metadata.v1.json

@@ -0,0 +1,79 @@
+{
+  "$schema": "../../schemas/catalog-metadata.v1.schema.json",
+  "schemaVersion": 1,
+  "identity": {
+    "kind": "skill",
+    "id": "python-runtime"
+  },
+  "presentation": {
+    "defaultLocale": "en-US",
+    "i18n": {
+      "zh-CN": {
+        "name": "Python 运行时管理",
+        "summary": "Python 安装、多版本与虚拟环境（DesireCore Hatch 优先）",
+        "description": "Use this skill when the user needs to install, upgrade, or troubleshoot Python and pip environments. Covers four-tier fallback strategy: (1) DesireCore HTTP API for in-app installation, (2) DesireCore built-in Hatch CLI for Python version management, (3) system package managers (brew/apt/dnf/winget), (4) community pyenv as last resort. Also covers virtual environments (venv/pipx/conda), PEP 668 externally-managed errors, and import / PATH troubleshooting. Triggers include: \"install python\", \"pip not found\", \"python not found\", \"PEP 668\", \"externally-managed\", \"venv\", \"virtualenv\", \"pipx\", \"conda\", \"miniconda\", \"pyenv\", \"hatch\", \"python version\", \"pip command not found\", or any Python-related runtime error. 使用场景：用户需要 安装 Python、安装 pip、配置虚拟环境、管理多版本、 解决 PEP 668、import 失败、PATH 问题、SSL 证书错误等。"
+      },
+      "en-US": {
+        "name": "Python Runtime Management",
+        "summary": "Python install, multi-version, and virtual envs (DesireCore Hatch first)",
+        "description": "Use this skill when the user needs to install, upgrade, or troubleshoot Python and pip environments. Covers four-tier fallback strategy: (1) DesireCore HTTP API for in-app installation, (2) DesireCore built-in Hatch CLI for Python version management, (3) system package managers (brew/apt/dnf/winget), (4) community pyenv as last resort. Also covers virtual environments (venv/pipx/conda), PEP 668 externally-managed errors, and import / PATH troubleshooting. Triggers include: \"install python\", \"pip not found\", \"python not found\", \"PEP 668\", \"externally-managed\", \"venv\", \"virtualenv\", \"pipx\", \"conda\", \"miniconda\", \"pyenv\", \"hatch\", \"python version\", \"pip command not found\", or any Python-related runtime error. Use when the user needs to install Python, install pip, configure virtual environments, manage multiple versions, resolve PEP 668, import failures, PATH issues, SSL certificate errors, etc."
+      }
+    },
+    "category": "development",
+    "tags": [
+      "python",
+      "pip",
+      "hatch",
+      "pyenv",
+      "venv",
+      "virtualenv",
+      "pipx",
+      "conda",
+      "environment"
+    ]
+  },
+  "release": {
+    "state": "known",
+    "version": "1.0.3",
+    "versionScheme": "semver"
+  },
+  "timestamps": {
+    "catalogUpdatedAt": {
+      "state": "known",
+      "value": "2026-07-07T13:14:31Z",
+      "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"
+    }
+  },
+  "spec": {
+    "kind": "skill",
+    "riskLevel": "low",
+    "skillType": "procedural"
+  }
+}