Revert "Merge data-apps specific migrations into one"

This reverts commit 383a5fa28d.

resources/migrations/064/20260528_data_app.yaml

@@ -2,7 +2,7 @@
 ##
 ## Data apps come from the repository connected via the remote-sync feature. The
 ## repo root has a `data_apps/` directory; each subdirectory is one app and
-## contains a `data_app.yaml` (name/path/allowed_hosts) plus its built bundle. Each app dir
+## contains a `data_app.yaml` (name/path) plus its built bundle. Each app dir
 ## is materialized as one row in this table on sync. The `bundle` / `bundle_hash`
 ## columns cache the last successfully synced bytes (nullable until first sync).
 
@@ -41,12 +41,6 @@ databaseChangeLog:
                   remarks: Human-readable name from the manifest, shown in the admin UI
                   constraints:
                     nullable: false
-              - column:
-                  name: allowed_hosts
-                  type: ${text.type}
-                  remarks: JSON array of origins the sandboxed bundle may fetch/XHR. NULL when none configured.
-                  constraints:
-                    nullable: true
               - column:
                   name: bundle_path
                   type: varchar(1024)
@@ -146,30 +140,3 @@ databaseChangeLog:
       # rollback drops it. Reverting the column first would only run right before
       # that DROP (and could fail once the table is gone). See the bundle changeset.
       rollback: []
-
-  - changeSet:
-      id: v64.2026-05-28T00:00:03
-      author: timofei
-      comment: >-
-        Add data_app.allowed_hosts. A JSON array of origins the app's sandboxed
-        bundle may fetch/XHR; NULL/empty means none. Guarded so pre-existing
-        tables pick it up while fresh installs that already created it skip it.
-      preConditions:
-        - onFail: MARK_RAN
-        - not:
-            - columnExists:
-                tableName: data_app
-                columnName: allowed_hosts
-      changes:
-        - addColumn:
-            tableName: data_app
-            columns:
-              - column:
-                  name: allowed_hosts
-                  type: ${text.type}
-                  remarks: JSON array of origins the sandboxed bundle may fetch/XHR. NULL when none configured.
-                  constraints:
-                    nullable: true
-      # No-op rollback: created in the same deployment as the table, whose own
-      # rollback drops it (see the enabled/bundle changesets).
-      rollback: []

resources/migrations/064/20260528_data_app_allowed_hosts.yaml

@@ -0,0 +1,34 @@
+## Adds data_app.allowed_hosts — a JSON array of origins the app's sandboxed
+## bundle may fetch/XHR (NULL/empty means none).
+##
+## Split into its own file rather than appended to 20260528_data_app.yaml so the
+## table-creation migration stays self-contained. The changeset is guarded with
+## `onFail: MARK_RAN` on `not columnExists`, so an instance that already added
+## this column under the earlier branch state fails the precondition and is
+## marked as ran (no re-run); fresh installs apply it normally.
+
+databaseChangeLog:
+  - changeSet:
+      id: v64.2026-05-28T00:00:03
+      author: timofei
+      comment: >-
+        Add data_app.allowed_hosts. A JSON array of origins the app's sandboxed
+        bundle may fetch/XHR; NULL/empty means none. Guarded so pre-existing
+        tables pick it up while fresh installs that already created it skip it.
+      preConditions:
+        - onFail: MARK_RAN
+        - not:
+            - columnExists:
+                tableName: data_app
+                columnName: allowed_hosts
+      changes:
+        - addColumn:
+            tableName: data_app
+            columns:
+              - column:
+                  name: allowed_hosts
+                  type: ${text.type}
+                  remarks: JSON array of origins the sandboxed bundle may fetch/XHR. NULL when none configured.
+                  constraints:
+                    nullable: true
+      rollback: []