fix(docs): update custom-agent docs to use required 'name' field

frontend/src/content/en/application/agents-and-threads.mdx

@@ -19,7 +19,7 @@ The default agent is the Lead Agent with no custom configuration. It loads all g
 
 Custom agents are named variants of the Lead Agent. Each one can have:
 
-- a **display name** and an auto-derived ASCII slug (the `name` used internally)
+- a **name** (caller-provided unique ASCII slug, e.g. `data-analyst`) and an optional **description**
 - a specific **model** to use by default
 - a restricted set of **skills** (or all globally enabled skills if unspecified)
 - a restricted set of **tool groups**
@@ -30,7 +30,7 @@ Custom agents are created and managed through:
 - **The App UI**: open the Agents section in the settings panel.
 - **The Gateway API**: `POST /api/agents` with the agent definition.
 
-The slug (`name`) is automatically derived from the `display_name` and must be unique. The system checks for conflicts and appends a suffix if needed (`/api/agents/check`).
+You provide a unique ASCII `name` matching `^[A-Za-z0-9-]+` (stored lowercase). Use `/api/agents/check` to verify availability before creation.
 
 Agent configuration is stored in `agents/{name}/config.yaml` relative to the backend directory.
 
@@ -41,7 +41,6 @@ To restrict a custom agent to specific skills:
 ```yaml
 # agents/my-researcher/config.yaml
 name: my-researcher
-display_name: My Researcher
 skills:
   - deep-research
   - academic-paper-review

frontend/src/content/en/harness/lead-agent.mdx

@@ -132,7 +132,7 @@ Plan mode is appropriate for complex, multi-step tasks where showing incremental
 
 The same Lead Agent runtime powers both the default agent and any custom agents you create. A custom agent differs only in:
 
-- its **name** (ASCII slug, auto-derived from `display_name`),
+- its **name** (unique ASCII identifier, e.g. `data-analyst`),
 - its **system prompt** or agent-specific instructions,
 - which **skills** it has access to,
 - which **tool groups** it can use, and

frontend/src/content/zh/application/agents-and-threads.mdx

@@ -39,7 +39,7 @@ DeerFlow 允许你创建多个具有不同专业领域的自定义 Agent。每
 curl -X POST http://localhost:8001/api/agents \
   -H "Content-Type: application/json" \
   -d '{
-    "display_name": "数据分析师",
+    "name": "data-analyst",
     "description": "专业的数据分析和可视化",
     "skills": ["data-analysis", "chart-visualization"]
   }'
@@ -49,12 +49,7 @@ curl -X POST http://localhost:8001/api/agents \
 
 ### Agent 名称和 Slug
 
-创建 Agent 时，`display_name` 对用户显示，系统内部使用自动派生的 ASCII `slug`（`name` 字段）来标识 Agent。
-
-- `display_name`：对用户显示的任意字符串（例如 "数据分析师"）
-- `name`（slug）：用于 API 和文件路径的 ASCII 标识符（例如 `data-analyst`）
-
-如果派生的 slug 与现有 Agent 冲突，`/api/agents/check` 端点会建议一个唯一的替代名称。
+你需要提供一个唯一的 ASCII `name`，匹配 `^[A-Za-z0-9-]+`（存储时转为小写）。创建前可使用 `/api/agents/check` 验证名称是否可用。
 
 ### Agent 存储
 

frontend/src/content/zh/harness/lead-agent.mdx

@@ -115,7 +115,7 @@ models:
 
 相同的 Lead Agent 运行时同时为默认 Agent 和你创建的任何自定义 Agent 提供服务。自定义 Agent 的区别仅在于：
 
-- 其**名称**（ASCII slug，从 `display_name` 自动派生）
+- 其**名称**（唯一 ASCII 标识符，例如 `data-analyst`）
 - 其**系统提示**或 Agent 特定指令
 - 它有权访问的**技能**
 - 它可以使用的**工具组**