refactor: 重构 Agent 模块为 AgentScope，删除旧版 CrewAI/LiteLLM 实现

backend/alembic/versions/20260226_0004_collaboration_tables.py

@@ -147,7 +147,7 @@ def upgrade() -> None:
         "ALTER TABLE schedule_subscriptions ADD CONSTRAINT chk_schedule_subscription_notify_level CHECK (notify_level IN ('all', 'mentions', 'none'))"
     )
     op.execute(
-        "ALTER TABLE schedule_subscriptions ADD CONSTRAINT chk_schedule_subscription_status CHECK (status IN ('active', 'paused', 'unsubscribed'))"
+        "ALTER TABLE schedule_subscriptions ADD CONSTRAINT chk_schedule_subscription_status CHECK (status IN ('active', 'paused', 'unsubscribed', 'pending'))"
     )
     op.create_foreign_key(
         "fk_schedule_subscriptions_item_id",

backend/alembic/versions/20260227_0006_invite_codes_and_profile_referral.py

@@ -52,11 +52,11 @@ def upgrade() -> None:
 
     op.execute(
         """
-        CREATE OR REPLACE FUNCTION public.generate_invite_code()
-        RETURNS TEXT
+        CREATE OR REPLACE FUNCTION public.create_profile_for_new_user()
+        RETURNS trigger
         LANGUAGE plpgsql
         SECURITY DEFINER
-        SET search_path = public
+        SET search_path = ''
         AS $$
         DECLARE
             chars TEXT := 'ABCDEFGHJKMNPQRSTUVWXYZ23456789';
@@ -159,7 +159,7 @@ def downgrade() -> None:
         RETURNS trigger
         LANGUAGE plpgsql
         SECURITY DEFINER
-        SET search_path = public
+        SET search_path = ''
         AS $$
         BEGIN
             INSERT INTO public.profiles (id, username, avatar_url, bio, settings, created_at, updated_at)