CREATE TABLE IF NOT EXISTS ai_shared_conversation ( id UUID PRIMARY KEY DEFAULT gen_random_uuid(), conversation_id UUID NOT NULL, share_token VARCHAR(128) UNIQUE NOT NULL, created_by UUID NOT NULL, view_count INT NOT NULL DEFAULT 0, created_at TIMESTAMPTZ NOT NULL DEFAULT NOW(), expires_at TIMESTAMPTZ ); CREATE INDEX IF NOT EXISTS idx_ai_share_conv ON ai_shared_conversation (conversation_id); CREATE INDEX IF NOT EXISTS idx_ai_share_token ON ai_shared_conversation (share_token); ALTER TABLE ai_shared_conversation ADD CONSTRAINT fk_ai_share_conv FOREIGN KEY (conversation_id) REFERENCES ai_conversation(id) ON DELETE CASCADE;