Finish long-running agent parity

migrations/20260726220000_add_compaction_messages/down.sql

@@ -0,0 +1,2 @@
+ALTER TABLE messages DROP COLUMN compaction_tail_start;
+ALTER TABLE messages DROP COLUMN compaction;

migrations/20260726220000_add_compaction_messages/up.sql

@@ -0,0 +1,2 @@
+ALTER TABLE messages ADD COLUMN compaction BOOLEAN NOT NULL DEFAULT FALSE;
+ALTER TABLE messages ADD COLUMN compaction_tail_start INTEGER;