feat: 模型配置支持删除，岗位行动规划对接任务系统字典与批量新增 Skill

模型管理新增 DELETE 接口与前端删除能力（支持含斜杠的模型名）；行动规划改为 9 字段 JSON，prepare 传入 taskId/字典并绑定 position-roundtable-action-create Skill。

Co-authored-by: Cursor <cursoragent@cursor.com>

.gitignore

@@ -77,8 +77,8 @@ offline-backend-20260512/backend/.deer-flow/*
 
 # Per-user skill_evolution overrides — runtime data written by the API
 offline-backend-20260512/backend/skill_evolution.json
-skills/
-hermes-agent-main/
+skills/
+hermes-agent-main/
 .gitignore
 offline-backend-20260512/backend/tests/*
 # Keep the model configuration regression coverage versioned even though