fix(db): add down migration, template-DB test harness, EntryStatus type

Co-Authored-By: Claude Sonnet 5.5 <noreply@anthropic.com>

packages/db/src/migrations/0001_initial.ts

@@ -389,4 +389,37 @@ export const initial: Migration = {
       { indexes: [["status", "run_at"], ["lock_key"]] },
     );
   },
+
+  async down(db: Kysely<any>) {
+    for (const table of [
+      "jobs",
+      "change_events",
+      "source_record_versions",
+      "source_records",
+      "source_runs",
+      "match_suggestions",
+      "user_history",
+      "attachment_links",
+      "attachments",
+      "copies",
+      "custom_field_definitions",
+      "list_items",
+      "lists",
+      "listens",
+      "engagement_sources",
+      "source_connections",
+      "engagements",
+      "entries",
+      "work_history",
+      "work_aliases",
+      "external_ids",
+      "works",
+      "app_tokens",
+      "invites",
+      "sessions",
+      "users",
+    ]) {
+      await db.schema.dropTable(table).execute();
+    }
+  },
 };