fix(database): add DELETED to conversations status CHECK constraint

用户删除历史对话时报错 conversations_status_check 违反约束，
因为 softDelete() 设置 status='DELETED' 但数据库 CHECK 约束
只允许 ACTIVE/ENDED/ARCHIVED。

修复：
- 新增 migration 修改 CHECK 约束，添加 DELETED 值
- 同步更新 init.sql 以支持全新部署

生产环境需执行：
database/migrations/20260207_add_deleted_status_to_conversations.sql

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

database/migrations/20260207_add_deleted_status_to_conversations.sql

@@ -0,0 +1,10 @@
+-- Migration: Add 'DELETED' to conversations status CHECK constraint
+-- 修复：软删除功能需要 DELETED 状态，但数据库 CHECK 约束未包含该值
+-- 导致用户无法删除历史对话（QueryFailedError: conversations_status_check）
+
+-- 删除旧约束
+ALTER TABLE conversations DROP CONSTRAINT IF EXISTS conversations_status_check;
+
+-- 添加包含 DELETED 的新约束
+ALTER TABLE conversations ADD CONSTRAINT conversations_status_check
+    CHECK (status IN ('ACTIVE', 'ENDED', 'ARCHIVED', 'DELETED'));

infrastructure/docker/services/postgres/init.sql

@@ -62,9 +62,9 @@ CREATE TABLE conversations (
     id UUID PRIMARY KEY DEFAULT uuid_generate_v4(),
     -- 所属用户ID
     user_id UUID REFERENCES users(id) ON DELETE CASCADE,
-    -- 对话状态: ACTIVE(进行中), ENDED(已结束), ARCHIVED(已归档)
+    -- 对话状态: ACTIVE(进行中), ENDED(已结束), ARCHIVED(已归档), DELETED(软删除)
     status VARCHAR(20) NOT NULL DEFAULT 'ACTIVE'
-        CHECK (status IN ('ACTIVE', 'ENDED', 'ARCHIVED')),
+        CHECK (status IN ('ACTIVE', 'ENDED', 'ARCHIVED', 'DELETED')),
     -- 对话标题（自动生成或用户设置）
     title VARCHAR(255),
     -- 对话摘要（AI生成）