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/__init__.py

@@ -104,7 +104,13 @@ from .plugins import plugin_manager
 # defeated by rotating the header. The helper resolves from remote_addr, which
 # ProxyFix has already filled from the header when TRUSTED_PROXY_COUNT says a
 # proxy is really in front. Additive names on the surface, minor bump.
-__contract_version__ = '0.29.0'
+# 0.30.0: added ImportBatch, ImportJournalEntry, and the BATCH_*/OP_* constants
+# to shopdb.api so a plugin's bulk-import UI can list applied import batches and
+# reverse one through the shared reversible journal without importing core model
+# internals. The journal records the primitive mutations a bulk import makes
+# (update a cell, insert a row) tied to a batch id, and a generic undo replays
+# them in reverse. Additive names on the surface, minor bump.
+__contract_version__ = '0.30.0'
 
 # Product release version (see ADR-007). The product version and the
 # plugin-contract version above are distinct series with independent