feat(life): implement soft delete for life posts

Add deleted_at and deleted_by_user_id to life_posts schema
Update queries to filter out and prevent interactions with deleted posts

DESIGN.md

@@ -378,10 +378,11 @@ Life Post 可配置：
 - 所有人都可以浏览 Life 信息流。
 - 信息流按创建时间倒序展示。
 - 已注册并完成邮箱验证的用户可以发布 Life Post。
-- 作者本人可以编辑、删除自己的 Life Post。
+- 作者本人可以编辑、删除自己的 Life Post；删除 Life Post 使用软删除。
 - 已注册并完成邮箱验证的用户发布或编辑 Life Post 时可以选择一个或多个 Life 标签。
 - 已注册并完成邮箱验证的用户可以评论 Life Post，并回复顶层评论。
 - 评论作者可以删除自己的评论；删除评论后正文不再展示，已有回复保留在原位置。
+- 已软删除的 Life Post 不出现在信息流、搜索或标签筛选结果中，也不能继续编辑、评论或设置 Reaction。
 - 每条 Life Post 默认只展示评论入口与评论数量；评论列表、回复和评论输入默认折叠，用户点击后展开。
 - 已注册并完成邮箱验证的用户可以对每条 Life Post 选择一个 Reaction；普通点击默认设置 `like`，再次点击 `like` 会取消，当前为其他 Reaction 时普通点击会替换为 `like`。
 - Life Reaction 的其他类型通过右键 / context menu 打开 Popup 选择；再次选择当前 Reaction 会取消，选择其他 Reaction 会替换原 Reaction。
@@ -399,6 +400,7 @@ API 暴露边界：
 - Life Reaction 对外只返回按类型汇总的数量和当前用户自己的 Reaction，不返回其他用户的 Reaction 明细。
 - Life Post 列表 API 返回分页结果：`items`、`nextCursor`、`hasMore`；`cursor` 是不透明分页令牌。
 - API 不返回邮箱、token/hash、内部调试字段或不必要的审计 payload。
+- API 不返回 Life Post 的 `deleted_at`、`deleted_by_user_id` 等内部软删除字段。
 - 非作者不能编辑或删除其他用户的 Life Post。
 - 非作者不能删除其他用户的 Life Comment。
 

backend/db/schema.sql

@@ -136,16 +136,24 @@ CREATE TABLE IF NOT EXISTS life_posts (
   body text NOT NULL CHECK (length(body) BETWEEN 1 AND 2000),
   created_by_user_id integer REFERENCES users(id) ON DELETE SET NULL,
   updated_by_user_id integer REFERENCES users(id) ON DELETE SET NULL,
+  deleted_by_user_id integer REFERENCES users(id) ON DELETE SET NULL,
+  deleted_at timestamptz,
   created_at timestamptz NOT NULL DEFAULT now(),
   updated_at timestamptz NOT NULL DEFAULT now()
 );
 
 ALTER TABLE life_posts DROP COLUMN IF EXISTS link_url;
 ALTER TABLE life_posts DROP COLUMN IF EXISTS link_title;
+ALTER TABLE life_posts ADD COLUMN IF NOT EXISTS deleted_by_user_id integer REFERENCES users(id) ON DELETE SET NULL;
+ALTER TABLE life_posts ADD COLUMN IF NOT EXISTS deleted_at timestamptz;
 
 CREATE INDEX IF NOT EXISTS life_posts_created_at_idx
   ON life_posts(created_at DESC, id DESC);
 
+CREATE INDEX IF NOT EXISTS life_posts_active_created_at_idx
+  ON life_posts(created_at DESC, id DESC)
+  WHERE deleted_at IS NULL;
+
 CREATE TABLE IF NOT EXISTS life_post_tags (
   post_id integer NOT NULL REFERENCES life_posts(id) ON DELETE CASCADE,
   tag_id integer NOT NULL REFERENCES life_tags(id) ON DELETE CASCADE,

backend/src/queries.ts

@@ -1509,7 +1509,7 @@ export async function listLifePosts(
   const search = asString(paramsQuery.search)?.trim();
   const tagIdValue = asString(paramsQuery.tagId)?.trim();
   const params: unknown[] = [];
-  const conditions: string[] = [];
+  const conditions: string[] = ['lp.deleted_at IS NULL'];
 
   if (search) {
     params.push(`%${search}%`);
@@ -1562,6 +1562,7 @@ async function getLifePostById(id: number, userId: number | null = null, locale
     `
       ${lifePostProjection(locale)}
       WHERE lp.id = $1
+        AND lp.deleted_at IS NULL
     `,
     [id]
   );
@@ -1620,6 +1621,7 @@ export async function updateLifePost(id: number, payload: Record<string, unknown
         SET body = $1, updated_by_user_id = $2, updated_at = now()
         WHERE id = $3
           AND created_by_user_id = $2
+          AND deleted_at IS NULL
         RETURNING id
       `,
       [cleanPayload.body, userId, id]
@@ -1640,9 +1642,14 @@ export async function updateLifePost(id: number, payload: Record<string, unknown
 export async function deleteLifePost(id: number, userId: number) {
   const result = await queryOne<{ id: number }>(
     `
-      DELETE FROM life_posts
+      UPDATE life_posts
+      SET deleted_at = now(),
+          deleted_by_user_id = $2,
+          updated_by_user_id = $2,
+          updated_at = now()
       WHERE id = $1
         AND created_by_user_id = $2
+        AND deleted_at IS NULL
       RETURNING id
     `,
     [id, userId]
@@ -1663,7 +1670,12 @@ export async function setLifePostReaction(
     `
       INSERT INTO life_post_reactions (post_id, user_id, reaction_type)
       SELECT $1, $2, $3
-      WHERE EXISTS (SELECT 1 FROM life_posts WHERE id = $1)
+      WHERE EXISTS (
+        SELECT 1
+        FROM life_posts
+        WHERE id = $1
+          AND deleted_at IS NULL
+      )
       ON CONFLICT (post_id, user_id)
       DO UPDATE SET reaction_type = EXCLUDED.reaction_type, updated_at = now()
       RETURNING post_id AS "postId"
@@ -1680,6 +1692,12 @@ export async function deleteLifePostReaction(postId: number, userId: number, loc
       DELETE FROM life_post_reactions
       WHERE post_id = $1
         AND user_id = $2
+        AND EXISTS (
+          SELECT 1
+          FROM life_posts
+          WHERE id = $1
+            AND deleted_at IS NULL
+        )
       RETURNING post_id AS "postId"
     `,
     [postId, userId]
@@ -1695,7 +1713,12 @@ export async function createLifeComment(postId: number, payload: Record<string,
     `
       INSERT INTO life_post_comments (post_id, body, created_by_user_id)
       SELECT $1, $2, $3
-      WHERE EXISTS (SELECT 1 FROM life_posts WHERE id = $1)
+      WHERE EXISTS (
+        SELECT 1
+        FROM life_posts
+        WHERE id = $1
+          AND deleted_at IS NULL
+      )
       RETURNING id
     `,
     [postId, cleanPayload.body, userId]
@@ -1717,10 +1740,12 @@ export async function createLifeCommentReply(
       INSERT INTO life_post_comments (post_id, parent_comment_id, body, created_by_user_id)
       SELECT lc.post_id, lc.id, $3, $4
       FROM life_post_comments lc
+      JOIN life_posts lp ON lp.id = lc.post_id
       WHERE lc.post_id = $1
         AND lc.id = $2
         AND lc.parent_comment_id IS NULL
         AND lc.deleted_at IS NULL
+        AND lp.deleted_at IS NULL
       RETURNING id
     `,
     [postId, commentId, cleanPayload.body, userId]