i18n(skills): localise SkillsSection strings

SkillsSection had nine hardcoded English strings (header, filter
placeholder/aria-label, empty-state copy, button labels). Move them to
skills.* keys in en.ts/zh.ts and swap the component to useT().

src/renderer/i18n/en.ts

@@ -190,6 +190,15 @@ export const en: Record<string, string> = {
   "agent.saveChanges": "Save changes",
   "agent.delete": "Delete agent",
   "agent.skills": "Skills",
+  "skills.title": "Skills",
+  "skills.importAria": "Import skill",
+  "skills.filterPlaceholder": "Filter skills...",
+  "skills.filterAria": "Filter skills",
+  "skills.emptyTitle": "No skills imported",
+  "skills.emptyDetail": "Import skills from GitHub, a local path, or skills.sh to get started.",
+  "skills.importButton": "Import Skill",
+  "skills.selectToViewTitle": "Select a skill to view details",
+  "skills.selectToViewDetail": "Choose a skill from the list to see its content, file tree, and configuration.",
   "agent.pendingApproval": "Pending Approval",
   "agent.pendingHireNote": "Pending hires must be approved or rejected from Hiring or Approvals.",
 

src/renderer/i18n/zh.ts

@@ -190,6 +190,15 @@ export const zh: Record<string, string> = {
   "agent.saveChanges": "保存",
   "agent.delete": "删除",
   "agent.skills": "技能",
+  "skills.title": "技能",
+  "skills.importAria": "导入技能",
+  "skills.filterPlaceholder": "过滤技能...",
+  "skills.filterAria": "过滤技能",
+  "skills.emptyTitle": "尚未导入技能",
+  "skills.emptyDetail": "从 GitHub、本地路径或 skills.sh 导入技能即可开始。",
+  "skills.importButton": "导入技能",
+  "skills.selectToViewTitle": "选择一个技能查看详情",
+  "skills.selectToViewDetail": "从列表中选择一项，查看其内容、文件树与配置。",
   "agent.pendingApproval": "等待审批",
   "agent.pendingHireNote": "待审批成员需在招聘或审批页面处理。",