i18n(zh): unify Skills terminology in settings labels

Use "Skills" consistently in skillStorage title/description and
skillSync title to match the upstream Agent Skills wording and the
existing English label style used elsewhere on the settings page.

src/i18n/locales/zh.json

@@ -486,8 +486,8 @@
       "opencodeDesc": "OpenCode CLI"
     },
     "skillStorage": {
-      "title": "技能存储位置",
-      "description": "选择 CC Switch 存放技能主副本的目录",
+      "title": "Skills 存储位置",
+      "description": "选择 CC Switch 存放 Skills 主副本的目录",
       "ccSwitch": "CC Switch",
       "unified": "~/.agents/skills",
       "ccSwitchHint": "技能存储在 ~/.cc-switch/skills/，由 CC Switch 统一管理并同步到各应用。",
@@ -498,7 +498,7 @@
       "migrationPartial": "迁移了 {{migrated}} 个技能，{{errors}} 个失败，请查看日志"
     },
     "skillSync": {
-      "title": "Skill 同步方式",
+      "title": "Skills 同步方式",
       "description": "选择 Skills 的文件同步策略",
       "symlink": "软连接",
       "copy": "文件复制",