feat: 智能体精选排序与新对话智能体选择器

- 后端新增 featured_order 字段及精选排序 API（/agents/selector、/agents/{id}/featured、/agents/featured/order），移除 user_agent_pin 表
- 前端新对话页 (ChatPage) 与输入框 (InputBox) 接入 agent-selector，选中后跳转 AgentChatPage 并通过 sessionStorage 透传首条消息
- 新增管理员智能体管理弹窗 (agent-manage-dialog) 支持精选添加/移除/上下移动

offline-backend-20260512/backend/CLAUDE.md

@@ -233,7 +233,7 @@ FastAPI application on port 8001 with health check at `GET /health`. Set `GATEWA
 | **Skills** (`/api/skills`) | `GET /` - list skills (optional `search` fuzzy-name + `tag_id` filters; each item carries `tags` + owner-authored `detail`); `GET /{name}` - details; `PUT /{name}` - update enabled; `PUT /{name}/detail` - set the long-form `detail` text (custom skill: owner or admin; built-in/public: admin only — materializes a `skills` row on demand); `GET /{name}/content` - raw SKILL.md source, restricted to an admin or the publisher (custom-skill owner); other users get 403 and see only description + detail; `POST /install` - install from .skill archive (accepts standard optional frontmatter like `version`, `author`, `compatibility`) |
 | **Skills** (`/api/skills`) | `GET /` - list skills (optional `search` fuzzy-name + repeatable `tag_ids` multi-select filter, OR-matched; each item carries `tags` + owner-authored `detail`); `GET /{name}` - details; `PUT /{name}` - update enabled; `PUT /{name}/detail` - set the long-form `detail` text (custom skill: owner or admin; built-in/public: admin only — materializes a `skills` row on demand); `GET /{name}/content` - raw SKILL.md source, restricted to an admin or the publisher (custom-skill owner); other users get 403 and see only description + detail; `POST /install` - install from .skill archive (accepts standard optional frontmatter like `version`, `author`, `compatibility`) |
 | **Memory** (`/api/memory`) | `GET /` - memory data; `POST /reload` - force reload; `GET /config` - config; `GET /status` - config + data |
-| **Agents** (`/api/agents`) | `GET /` - list built-in, owned, and published agents (optional `search` + repeatable `tag_ids` multi-select filter, OR-matched; each item carries `tags`); `POST /` - create user-owned agent; `GET/PUT/DELETE /{id}` - read/update/delete by stable agent id; `GET /check` - validate non-empty display name (duplicates allowed) |
+| **Agents** (`/api/agents`) | `GET /` - list built-in, owned, and published agents (optional `search` + repeatable `tag_ids` multi-select filter, OR-matched; each item carries `tags` and `featured_order`); `POST /` - create user-owned agent; `GET/PUT/DELETE /{id}` - read/update/delete by stable agent id; `GET /check` - validate non-empty display name (duplicates allowed); `GET /selector` - homepage agent picker (single admin-curated list, visibility-filtered, sorted by `featured_order` asc); `PUT /{id}/featured` - **admin** sets/clears the homepage `featured_order` (must be `published=true` to feature; passing `order: null` clears unconditionally); `PUT /featured/order` - **admin** bulk-reorders the homepage list (body `{agent_ids: [...]}` → indices become 0..N-1) |
 | **Tags** (`/api/tags`) | `GET /` - list tags (optional `tag_type` filter; open to all); `POST /` - create tag (admin); `PUT /{id}` / `DELETE /{id}` - update/delete tag (admin); `GET /assignments/{target_type}/{target_id}` - tags on a resource; `PUT /assignments/{target_type}/{target_id}` - replace a resource's tags (admin). Tags are typed `agent`/`skill`/`scheduled_task` and may only tag resources of their own type. |
 | **Uploads** (`/api/threads/{id}/uploads`) | `POST /` - upload files (auto-converts PDF/PPT/Excel/Word); `GET /list` - list; `DELETE /{filename}` - delete |
 | **Threads** (`/api/threads/{id}`) | `DELETE /` - remove DeerFlow-managed local thread data after LangGraph thread deletion; unexpected failures are logged server-side and return a generic 500 detail |
@@ -260,6 +260,8 @@ Proxied through nginx: `/api/langgraph/*` → LangGraph, all other `/api/*` →
 
 Custom agent metadata lives in the `agents` ORM table (`deerflow.persistence.agents`). `agents.id` is the stable runtime id and the filesystem directory name under `.deer-flow/agents/{id}/`; `agents.name` is display-only, can contain Chinese characters, and is not unique. `user_id IS NULL` marks built-in agents, user-owned agents are visible only to their owner unless `published = true`, and update/delete operations require ownership. The runtime accepts `agent_id` in context/configurable, and non-default `assistant_id` values are treated as agent ids after visibility checks.
 
+**Homepage selector (agent picker on the new-chat page)** — single admin-curated list backed by `agents.featured_order` (nullable BIGINT). NULL = not featured. Only `published = true` agents can be featured (router enforces on writes); any published agent is eligible regardless of ownership. Cleared with `order: null`. The list rendered to end users is `WHERE featured_order IS NOT NULL` + visibility-filter, sorted by `featured_order ASC`. Admins reorder by sending the desired ids to `PUT /api/agents/featured/order` (assigns indices 0..N-1). BIGINT is used rather than INT so the management UI can seed initial values from `Date.now()` (overflows INT on MySQL).
+
 ### Portable Column Types (`deerflow/persistence/types.py`)
 
 Two `TypeDecorator`s keep ORM columns correct across the `sqlite` / `postgres` / `mysql` backends. **All ORM timestamp/JSON columns must use these, not the raw SQLAlchemy types.**