-- Drop per-topic announce target columns. The backend no longer
-- broadcasts lifecycle events to Fabric; the proposing agent posts a
-- single recruitment fabric-send-message after topic creation, and
-- downstream agents book HF on_call slots covering the debate window
-- via `hf calendar schedule` so HF wakes them naturally.
--
-- Counterpart of 002_topic_announce_target.sql (now obsolete).
ALTER TABLE topics
  DROP COLUMN announce_guild_base_url,
  DROP COLUMN announce_channel_id;