Add reversible Maximo/WINC machine-adoption import

Machine data arrives as a Maximo asset export (validated against the WINC
site) that must update existing machines in place, not create canonical
per-table rows, so it does not fit the ShopDB-native/Azure/Thor CSV adapter
path. Bulk edits to live machines also need an escape hatch, so the whole
commit is journaled and can be undone as one batch.

Add a dedicated dry-run analyzer, approval packet, resolver/suggest helpers,
and a reversible writer/undo backed by a new importbatches/importjournalentries
schema (with migration). Expose preview/commit/batches/undo settings routes and
a matching frontend source card and panel, and surface the batch/journal
contract through shopdb.api for plugins.

shopdb/api/__init__.py

@@ -140,6 +140,22 @@ from shopdb.utils.mailer import send_email, send_alert, send_webhook
 from shopdb.utils.cmmc_usb_db import cmmc_usb_connection
 
 
+# Reversible bulk-import journal. A plugin that drives a bulk import (a site
+# asset adoption, an integration sync) records the primitive changes it makes so
+# the whole batch can be undone. ImportBatch is the identity approval, write, and
+# undo all reference; ImportJournalEntry is one reversible mutation. Exposed so a
+# plugin's import UI can list applied batches and reverse one without reaching
+# into core internals. See docs/PLUGIN-HOOKS.md.
+from shopdb.core.models import (
+    ImportBatch,
+    ImportJournalEntry,
+    BATCH_APPLIED,
+    BATCH_UNDONE,
+    OP_UPDATE,
+    OP_INSERT,
+)
+
+
 def audit_log(
     action: str,
     entitytype: str,