feat(skills): 点击技能展示 SKILL.md 详情弹窗

- 后端新增 GET /api/skills/{name}/content 接口,返回公共/自定义技能的 SKILL.md 原文
- 前端技能行内容区可点击,弹窗以等宽原文展示 SKILL.md

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

offline-backend-20260512/backend/app/gateway/routers/skills.py

@@ -816,6 +816,36 @@ async def get_skill(skill_name: str, config: AppConfig = Depends(get_config)) ->
         raise HTTPException(status_code=500, detail=f"Failed to get skill: {str(e)}")
 
 
+class SkillContentResponse(BaseModel):
+    """SKILL.md 原文内容,适用于公共和自定义技能。"""
+
+    name: str
+    category: SkillCategory
+    content: str
+
+
+@router.get(
+    "/skills/{skill_name}/content",
+    response_model=SkillContentResponse,
+    summary="Get Skill Markdown Content",
+    description="Retrieve the raw SKILL.md content of a specific skill (public or custom).",
+)
+async def get_skill_content(skill_name: str, config: AppConfig = Depends(get_config)) -> SkillContentResponse:
+    try:
+        skill_name = skill_name.replace("\r\n", "").replace("\n", "")
+        skills = get_or_new_skill_storage(app_config=config).load_skills(enabled_only=False)
+        skill = next((s for s in skills if s.name == skill_name), None)
+        if skill is None:
+            raise HTTPException(status_code=404, detail=f"Skill '{skill_name}' not found")
+        content = skill.skill_file.read_text(encoding="utf-8")
+        return SkillContentResponse(name=skill.name, category=skill.category, content=content)
+    except HTTPException:
+        raise
+    except Exception as e:
+        logger.error("Failed to get skill content %s: %s", skill_name, e, exc_info=True)
+        raise HTTPException(status_code=500, detail=f"Failed to get skill content: {str(e)}")
+
+
 @router.put(
     "/skills/{skill_name}",
     response_model=SkillResponse,