Remove db migration code to init

api/app/main.py

@@ -2,42 +2,15 @@ from fastapi import FastAPI
 from fastapi.middleware.cors import CORSMiddleware
 from contextlib import asynccontextmanager
 import os
-from sqlalchemy import inspect, text
 
 from .db import Base, engine
 from .routers import assistants, voices, workflows, history, knowledge, llm, asr, tools
 
 
-def _ensure_assistant_columns() -> None:
-    """Best-effort SQLite schema evolution for assistant flags."""
-    inspector = inspect(engine)
-    if "assistants" not in inspector.get_table_names():
-        return
-
-    columns = {col["name"] for col in inspector.get_columns("assistants")}
-    alter_statements = []
-    if "generated_opener_enabled" not in columns:
-        alter_statements.append(
-            "ALTER TABLE assistants ADD COLUMN generated_opener_enabled BOOLEAN DEFAULT 0"
-        )
-    if "bot_cannot_be_interrupted" not in columns:
-        alter_statements.append(
-            "ALTER TABLE assistants ADD COLUMN bot_cannot_be_interrupted BOOLEAN DEFAULT 0"
-        )
-
-    if not alter_statements:
-        return
-
-    with engine.begin() as conn:
-        for stmt in alter_statements:
-            conn.execute(text(stmt))
-
-
 @asynccontextmanager
 async def lifespan(app: FastAPI):
     # 启动时创建表
     Base.metadata.create_all(bind=engine)
-    _ensure_assistant_columns()
     yield