update:1.重构项目数据库初始化和迁移逻辑，使用Alembic数据库管理工具

backend/alembic/postgres/env.py

@@ -0,0 +1,101 @@
+"""Alembic 环境配置文件 - PostgreSQL"""
+import asyncio
+import os
+import sys
+from logging.config import fileConfig
+
+from sqlalchemy import pool
+from sqlalchemy.engine import Connection
+from sqlalchemy.ext.asyncio import async_engine_from_config
+
+from alembic import context
+
+# 添加项目根目录到 Python 路径
+project_root = os.path.dirname(os.path.dirname(os.path.dirname(os.path.abspath(__file__))))
+if project_root not in sys.path:
+    sys.path.insert(0, project_root)
+
+# 导入应用配置
+from app.config import settings
+
+# 导入 Base 和所有模型
+from app.database import Base
+from app.models import (
+    Project, Outline, Character, Chapter, GenerationHistory,
+    Settings, WritingStyle, ProjectDefaultStyle,
+    RelationshipType, CharacterRelationship, Organization, OrganizationMember,
+    StoryMemory, PlotAnalysis, AnalysisTask, BatchGenerationTask,
+    RegenerationTask, Career, CharacterCareer, User, MCPPlugin, PromptTemplate
+)
+
+# Alembic Config 对象
+config = context.config
+
+# 设置数据库连接字符串（从环境变量读取）
+config.set_main_option("sqlalchemy.url", settings.database_url)
+
+# 配置日志
+if config.config_file_name is not None:
+    fileConfig(config.config_file_name)
+
+# 设置 target_metadata 为应用的 Base.metadata
+target_metadata = Base.metadata
+
+
+def run_migrations_offline() -> None:
+    """在'离线'模式下运行迁移"""
+    url = config.get_main_option("sqlalchemy.url")
+    context.configure(
+        url=url,
+        target_metadata=target_metadata,
+        literal_binds=True,
+        dialect_opts={"paramstyle": "named"},
+        compare_type=True,
+        compare_server_default=True,
+    )
+
+    with context.begin_transaction():
+        context.run_migrations()
+
+
+def do_run_migrations(connection: Connection) -> None:
+    """执行迁移的核心函数 - PostgreSQL 专用"""
+    context.configure(
+        connection=connection,
+        target_metadata=target_metadata,
+        compare_type=True,
+        compare_server_default=True,
+        render_as_batch=False,  # PostgreSQL 不需要批处理模式
+    )
+
+    with context.begin_transaction():
+        context.run_migrations()
+
+
+async def run_async_migrations() -> None:
+    """在'在线'模式下运行异步迁移"""
+    configuration = config.get_section(config.config_ini_section, {})
+    configuration["sqlalchemy.url"] = settings.database_url
+    
+    connectable = async_engine_from_config(
+        configuration,
+        prefix="sqlalchemy.",
+        poolclass=pool.NullPool,
+    )
+
+    async with connectable.connect() as connection:
+        await connection.run_sync(do_run_migrations)
+
+    await connectable.dispose()
+
+
+def run_migrations_online() -> None:
+    """在'在线'模式下运行迁移"""
+    asyncio.run(run_async_migrations())
+
+
+# 根据上下文选择运行模式
+if context.is_offline_mode():
+    run_migrations_offline()
+else:
+    run_migrations_online()