docs(contributors): add product design guide

docs/contributors/docs/index.en.md

@@ -2,7 +2,7 @@
 
 Welcome to the official documentation of **AlienCommons**.
 
-**AlienCommons** is a website currently designed to host documents and articles 
+**AlienCommons** is a website currently designed to host documents and articles
 translated by _**LazyAlienServer techMC Translation Team**_.
 
 ---
@@ -11,5 +11,6 @@ translated by _**LazyAlienServer techMC Translation Team**_.
 
 If you are new to this project, start from the following links:
 
+- [Product Design](product/index.en.md)
 - [Development Setup](development/setup.en.md)
 - [Project Architecture](architecture.en.md)

docs/contributors/docs/index.zh.md

@@ -10,5 +10,6 @@
 
 如果你第一次接触这个项目，请从以下链接开始：
 
+- [产品设计](product/index.zh.md)
 - [开发设置](development/setup.zh.md)
 - [项目架构](architecture.zh.md)

docs/contributors/docs/product/articles.en.md

@@ -0,0 +1,81 @@
+# Columns
+
+Formal columns are the core content type of AlienCommons. They are suitable for complete technical writing intended for long-term reading.
+
+## Basic Content
+
+A column contains:
+
+- A title
+- Body content
+- A cover image
+- A summary
+- One or more authors
+- Free-form tags entered by authors
+
+Whether the summary may be empty is still undecided. Categories and original-language metadata are not currently planned.
+
+## Body Capabilities
+
+The body may include:
+
+- Images
+- Code blocks
+- Mathematical formulas
+- External links
+- Video link cards for platforms such as YouTube and Bilibili
+
+Videos are not directly embedded or uploaded in the body. Video content is displayed only as link cards.
+
+## Displayed Information
+
+A column page displays:
+
+- Publication time
+- Last modification time
+- View count
+- Like count
+- Dislike count
+- Bookmark count
+
+## Work States
+
+The basic publishing flow is:
+
+```mermaid
+stateDiagram-v2
+    [*] --> Draft
+    Draft --> UnderReview: Author submits
+    UnderReview --> Draft: Author withdraws
+    UnderReview --> Published: Editor approves
+    UnderReview --> Draft: Editor rejects with feedback
+```
+
+Confirmed rules:
+
+- Editors may leave revision feedback but cannot modify the text directly.
+- A rejected work returns to the draft state.
+- A work can be deleted only while it is a draft.
+- Published works may be revised, but new versions must be reviewed again.
+- While a new version is under review, the previous version remains public.
+- The new version replaces the public version only after approval.
+- A work unpublished by an editor is not deleted.
+
+The state entered after unpublishing and whether an `Archived` state should be added are still undecided. See [Open Questions](open-questions.en.md).
+
+## Collections
+
+Authors may create collections to organize related works into a series.
+
+Collection rules:
+
+- A name is required.
+- A description and cover image are optional.
+- A work may belong to at most one collection.
+- The collection creator must be one of the work's authors.
+- The collection creator may manually reorder works.
+- A collection page displays its creation time, update time, and bookmark count.
+- Users may bookmark collections.
+- Collections do not have comment sections.
+
+Management permissions for multi-author works in collections are still undecided.

docs/contributors/docs/product/articles.zh.md

@@ -0,0 +1,81 @@
+# 专栏作品
+
+正式专栏是 AlienCommons 的核心内容类型。它适合完整、长期可读的技术表达。
+
+## 基本内容
+
+一篇专栏作品包含：
+
+- 标题
+- 正文
+- 封面图
+- 摘要
+- 一位或多位作者
+- 由作者自由填写的标签
+
+摘要是否允许为空仍待确定。当前不考虑分类，也不记录原文语言。
+
+## 正文能力
+
+正文允许插入：
+
+- 图片
+- 代码块
+- 数学公式
+- 外部链接
+- YouTube、Bilibili 等平台的视频链接卡片
+
+正文不直接嵌入或上传视频。视频内容仅以链接卡片形式展示。
+
+## 展示信息
+
+作品页面显示：
+
+- 发布时间
+- 最后修改时间
+- 浏览量
+- 点赞数
+- 点踩数
+- 收藏数
+
+## 作品状态
+
+基础发布流程如下：
+
+```mermaid
+stateDiagram-v2
+    [*] --> 草稿
+    草稿 --> 审核中: 作者提交
+    审核中 --> 草稿: 作者主动撤回
+    审核中 --> 已发布: 编辑通过
+    审核中 --> 草稿: 编辑拒绝并给出意见
+```
+
+已确认的规则：
+
+- 编辑可以给出修改意见，但不能直接修改正文。
+- 审核失败后，作品回到草稿状态。
+- 只有处于草稿状态的作品可以删除。
+- 已发布作品可以修改，但新版本需要重新审核。
+- 新版本审核期间，旧版本继续公开展示。
+- 新版本审核通过后，才会替换线上公开版本。
+- 被编辑撤稿的作品不会被删除。
+
+撤稿后应进入何种状态，以及是否增加 `Archived` 状态，仍待确定。参见[开放问题](open-questions.zh.md)。
+
+## 文集
+
+作者可以创建文集（Collection），将自己的相关作品组织成系列。
+
+文集规则如下：
+
+- 名称必填。
+- 简介和封面图可选。
+- 一篇作品最多加入一个文集。
+- 文集创建者必须是文章作者之一。
+- 文集创建者可以手动调整作品顺序。
+- 文集页面展示创建时间、更新时间和收藏数。
+- 用户可以收藏文集。
+- 文集不提供评论区。
+
+多人协作作品加入文集后的管理权限仍待确定。

docs/contributors/docs/product/community.en.md

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+# Community Interaction
+
+AlienCommons provides lightweight community interaction in addition to formal columns. Community features should support technical exchange without overshadowing columns as the platform's core content.
+
+## Work Interactions
+
+Users can interact with formal columns by:
+
+- Liking or disliking
+- Bookmarking
+- Commenting and replying
+- Following authors
+- Reporting
+
+## Community Posts
+
+Signed-in users may publish community posts. Similar to YouTube community posts, they support lighter and more immediate updates instead of the complete discussion expected from formal columns.
+
+- Short and medium-length content is allowed.
+- The length limit is tentatively around `500` words and remains undecided.
+- Images may be attached.
+- Likes, dislikes, comments, replies, and reports are supported.
+- Bookmarking is not supported.
+- There is currently no site-wide community feed.
+- A user's community posts are viewed through a dedicated tab on that user's profile.
+
+## Comments
+
+Columns and community posts share the same comment system.
+
+- Comments and replies both support likes, dislikes, and reports.
+- Replies may be nested in the data model.
+- The interface displays a consistent two-level structure similar to Bilibili.
+- Further replies to second-level comments use `@username` instead of additional visual indentation.
+- A column author or community-post author may pin one comment.
+- Users may edit or delete their own comments.
+- Edited comments display an `edited` indicator.
+- Comments display their publication time.
+
+## User Profiles
+
+A user profile displays:
+
+- Avatar
+- Username
+- Biography
+- Registration time
+- Published columns
+- Collections
+- Community posts
+- Follower count
+- Following count
+
+Users may follow, block, and report other users.
+
+## Bookmarks and Privacy
+
+- Every user may create bookmark folders.
+- Bookmark folders may contain formal columns from different authors.
+- Bookmark folders cannot be nested.
+- A bookmark folder may be public or private when created, and its visibility may be changed later.
+- Users choose whether their like and dislike history is public. It is private by default.

docs/contributors/docs/product/community.zh.md

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+# 社区互动
+
+AlienCommons 在正式专栏之外提供轻量社区互动。社区功能应服务于技术交流，不应掩盖专栏作品的核心地位。
+
+## 作品互动
+
+用户可以对正式专栏：
+
+- 点赞或点踩
+- 收藏
+- 评论与回复
+- 关注作者
+- 举报
+
+## 社区帖
+
+登录用户可以发表社区帖（Community Post）。它类似 YouTube 社区帖，用于较轻量、较即时的动态交流，不承担正式专栏的完整论述功能。
+
+- 允许短内容和中等长度内容。
+- 字数上限暂定约为 `500` 词，具体限制待确定。
+- 允许附带图片。
+- 支持点赞、点踩、评论、回复和举报。
+- 不允许收藏。
+- 当前不设独立的全站社区动态页面。
+- 用户通过个人主页中的专属 Tab 查看某位用户的社区帖。
+
+## 评论
+
+专栏和社区帖共用同一套评论机制。
+
+- 评论和回复都支持点赞、点踩和举报。
+- 数据层允许嵌套回复。
+- 前端统一采用类似 Bilibili 的两级展示结构。
+- 对二级评论的继续回复通过 `@用户名` 表达，不增加新的视觉缩进。
+- 专栏作者或社区帖作者可以置顶一条评论。
+- 用户可以编辑或删除自己的评论。
+- 编辑后的评论显示 `edited` 提示。
+- 评论显示发布时间。
+
+## 用户主页
+
+用户主页展示：
+
+- 头像
+- 用户名
+- 个人简介
+- 注册时间
+- 已发布专栏
+- 文集
+- 社区帖
+- 关注者数量
+- 正在关注的人数
+
+用户之间可以关注、拉黑和举报。
+
+## 收藏与隐私
+
+- 每位用户都可以创建收藏夹（Bookmark Folder）。
+- 收藏夹可以收录不同作者的正式专栏作品。
+- 收藏夹不允许嵌套。
+- 收藏夹创建时可以选择公开或私密，之后可以随时调整。
+- 点赞与点踩记录是否公开由用户自行选择，默认不可见。

docs/contributors/docs/product/discovery.en.md

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+# Content Discovery
+
+Users can discover columns through the home-page recommendation feed and search.
+
+## Home-Page Recommendations
+
+The home page centers on a work recommendation feed. Its discovery experience may draw from Bilibili and YouTube, but only formal columns are recommended.
+
+- Collections and community posts are not mixed into the home page.
+- Visitors and signed-in users can both view the recommendation feed.
+- Visitors receive random recommendations.
+- Signed-in users receive personalized recommendations.
+
+The specific recommendation algorithm is outside the scope of this product document.
+
+## Search
+
+Search is used only to discover columns.
+
+- Search results support filtering.
+- Search results support sorting.
+- The specific filter and sort options are still undecided.
+
+Collections, users, and community posts are not currently included in search.

docs/contributors/docs/product/discovery.zh.md

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+# 内容发现
+
+用户可以通过首页推荐流和搜索发现专栏作品。
+
+## 首页推荐
+
+首页以作品推荐流为核心，体验可以参考 Bilibili 和 YouTube，但推荐对象仅为正式专栏作品。
+
+- 首页不混入文集或社区帖。
+- 游客和已登录用户都可以看到推荐流。
+- 游客看到随机推荐。
+- 已登录用户看到个性化推荐。
+
+具体推荐算法不在当前产品文档中约束。
+
+## 搜索
+
+搜索仅用于发现专栏作品。
+
+- 搜索结果支持筛选。
+- 搜索结果支持排序。
+- 具体筛选项和排序项仍待确定。
+
+文集、用户和社区帖当前不属于搜索范围。