feat: manage_skill + 全局 skills 目录

新增:
- manage_skill: LLM 可调用的 Skill 创建/删除/列出工具 (High)
- 全局 skills 支持: ~/.ias/skills/ 自动加载
- SkillRegistry::register_skill() 动态注册
- SkillRegistry::load() 三元加载: system → global → user

manage_skill 操作:
  create: 写 SKILL.md + 执行脚本到 skills/<name>/
  delete: 移除 skills/<name>/
  list: 列出所有自定义 Skill

目前一共 9 个系统 Skills

resources/skills/manage_skill/SKILL.md

@@ -0,0 +1,49 @@
+# manage_skill
+
+管理 Skill：创建新的 Skill，列出所有已加载的 Skill，删除 Skill。
+
+创建的 Skill 会持久化到 `skills/` 目录，重启后自动加载。
+
+## Risk Level
+High
+
+## Parameters
+```json
+{
+  "type": "object",
+  "properties": {
+    "action": {
+      "type": "string",
+      "description": "操作类型",
+      "enum": ["create", "delete", "list"]
+    },
+    "name": {
+      "type": "string",
+      "description": "Skill 名称（create/delete 时需要）"
+    },
+    "description": {
+      "type": "string",
+      "description": "Skill 描述（create 时需要）"
+    },
+    "command": {
+      "type": "string",
+      "description": "Skill 执行的命令（create 时需要）"
+    },
+    "parameters": {
+      "type": "string",
+      "description": "参数 JSON Schema（create 时需要，JSON 字符串）"
+    },
+    "risk_level": {
+      "type": "string",
+      "description": "风险等级 Low|High，默认 Low",
+      "enum": ["Low", "High"]
+    }
+  },
+  "required": ["action"]
+}
+```
+
+## Execute
+```bash
+scripts/manage.sh
+```

resources/skills/manage_skill/scripts/manage.sh

@@ -0,0 +1,106 @@
+#!/bin/bash
+read -r INPUT
+export MANAGE_INPUT="$INPUT"
+
+python3 - "skills" << 'PYEOF'
+import sys, json, os, stat
+
+skills_dir = sys.argv[1]
+input_raw = os.environ.get('MANAGE_INPUT', '{}')
+
+try:
+    req = json.loads(input_raw) if input_raw else json.loads(sys.stdin.read())
+except:
+    print("无效的 JSON 输入")
+    sys.exit(1)
+
+action = req.get('action', 'list')
+name = req.get('name', '').strip()
+desc = req.get('description', '')
+command = req.get('command', '')
+params = req.get('parameters', '{"type":"object","properties":{}}')
+risk = req.get('risk_level', 'Low')
+
+os.makedirs(skills_dir, exist_ok=True)
+
+if action == 'list':
+    if not os.path.isdir(skills_dir):
+        print("skills 目录不存在")
+        sys.exit(0)
+    entries = [d for d in os.listdir(skills_dir) if os.path.isdir(os.path.join(skills_dir, d))]
+    if not entries:
+        print("暂无自定义 Skill")
+    else:
+        print("自定义 Skills:")
+        for d in sorted(entries):
+            md = os.path.join(skills_dir, d, "SKILL.md")
+            if os.path.exists(md):
+                first = open(md).readline().strip('# \n')
+                print(f"  • {d} — {first}")
+
+elif action == 'create':
+    if not name:
+        print("请提供 name 参数")
+        sys.exit(1)
+    if not command:
+        print("请提供 command 参数")
+        sys.exit(1)
+
+    skill_dir = os.path.join(skills_dir, name)
+    scripts_dir = os.path.join(skill_dir, "scripts")
+    os.makedirs(scripts_dir, exist_ok=True)
+
+    # 解析参数 JSON（美化）
+    try:
+        params_obj = json.loads(params) if isinstance(params, str) else params
+        params_pretty = json.dumps(params_obj, indent=2, ensure_ascii=False)
+    except:
+        params_pretty = params
+
+    # 写 SKILL.md
+    md_content = f"""# {name}
+
+{desc}
+
+## Risk Level
+{risk}
+
+## Parameters
+```json
+{params_pretty}
+```
+
+## Execute
+```bash
+scripts/main.sh
+```
+"""
+    with open(os.path.join(skill_dir, "SKILL.md"), "w") as f:
+        f.write(md_content.strip() + "\n")
+
+    # 写执行脚本
+    script = os.path.join(scripts_dir, "main.sh")
+    with open(script, "w") as f:
+        f.write(f"#!/bin/bash\n{command}\n")
+    os.chmod(script, 0o755)
+
+    print(f"✅ 已创建 Skill: {name}")
+    print(f"   位置: {skill_dir}")
+    print(f"   风险: {risk}")
+
+elif action == 'delete':
+    if not name:
+        print("请提供 name 参数")
+        sys.exit(1)
+    skill_dir = os.path.join(skills_dir, name)
+    if not os.path.isdir(skill_dir):
+        print(f"Skill 不存在: {name}")
+        sys.exit(1)
+    import shutil
+    shutil.rmtree(skill_dir)
+    print(f"✅ 已删除 Skill: {name}")
+
+else:
+    print(f"未知操作: {action}（支持: create, delete, list）")
+    sys.exit(1)
+PYEOF