M2b：删除旧 chat 体系——线性会话/叩心/情绪/纪念日模型与页面退役（迁移 003 双向验证），runs 去会话外键，测试全量修剪

backend/app/api/router.py

@@ -9,7 +9,6 @@ from app.api.v1.endpoints import (
     avatar,
     character_import,
     characters,
-    chat,
     drive,
     events,
     evolution,
@@ -30,7 +29,6 @@ from app.api.v1.endpoints import (
     sandbox_files,
     settings,
     skills,
-    time,
     tools,
     world,
 )
@@ -40,7 +38,6 @@ api_router.include_router(health.router)
 api_router.include_router(auth.router)
 api_router.include_router(characters.router)
 api_router.include_router(character_import.router)
-api_router.include_router(chat.router)
 api_router.include_router(runs.router)
 api_router.include_router(kernel_runs.router)
 api_router.include_router(embryo_drafts.router)
@@ -66,4 +63,3 @@ api_router.include_router(goals.router)
 api_router.include_router(admin.router)
 api_router.include_router(audio.router)
 api_router.include_router(avatar.router)
-api_router.include_router(time.router)