Wire measuring tools into identifiers and global search

The measuringtools plugin was missing from two cross-cutting surfaces:
the asset-identifier matrix (no measuring_tool column or per-type
keys - gauge lab reference is their primary identifier) and global
search (results fell to a generic URL and gaugelabreference was never
searched). Measuring tools now have identifier toggles, gated
gauge-lab and maintenance-reference fields on their form and detail,
a search domain toggle, gage-tag search, and proper labels, routes,
and filter chips in search results.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

plugins/measuringtools/api/routes.py

@@ -249,6 +249,7 @@ def create_tool():
         assetnumber=data['assetnumber'],
         name=data.get('name'),
         gaugelabreference=data.get('gaugelabreference'),
+        maintenancereference=data.get('maintenancereference'),
         serialnumber=data.get('serialnumber'),
         assettypeid=assettypeid,
         statusid=data.get('statusid', 1),
@@ -281,7 +282,8 @@ def create_tool():
 
 
 # Asset core fields writable through this plugin's write path.
-_ASSET_FIELDS = ('assetnumber', 'name', 'gaugelabreference', 'serialnumber',
+_ASSET_FIELDS = ('assetnumber', 'name', 'gaugelabreference',
+                 'maintenancereference', 'serialnumber',
                  'statusid', 'locationid', 'businessunitid', 'mapx', 'mapy',
                  'notes', 'isactive')
 # Extension fields with plain assignment (dates handled separately).