add Entra device identity to computers and Azure/Thor import sources

PC records now carry Entra/Azure device identity so imported machines keep a durable link back to their directory object instead of matching on hostname alone. Adds azuredeviceid, azureobjectid, and azuredevicecategory to the Computer model with matching migrations, surfaces them read-only in PCDetail as an Entra Device Info card, and lets PCForm edit the device id directly. The computers plugin registers a machineassetnumber import hook that reconciles PC-to-machine links during bulk import and warns on unresolved or conflicting relationships.

Adds importsources adapters that normalize Azure device-group and Thor PC inventory exports into canonical ShopDB CSVs via hostname alignment, exposes register_import_hook and RowWarning on the shopdb.api contract surface (contract 0.21.0), and refreshes the Import Site Assets page with clearer source instructions. Includes reconcile_locations maintenance script and coverage for the new import paths.

plugins/computers/models/computer.py

@@ -85,6 +85,23 @@ class Computer(BaseModel):
     lastreporteddate = db.Column(db.DateTime, nullable=True)
     lastboottime = db.Column(db.DateTime, nullable=True)
 
+    # Entra/Azure device identity (set by Azure device-group imports)
+    azuredeviceid = db.Column(
+        db.String(64),
+        nullable=True,
+        comment='Entra/Azure deviceId GUID'
+    )
+    azureobjectid = db.Column(
+        db.String(64),
+        nullable=True,
+        comment='Entra/Azure directory object id GUID'
+    )
+    azuredevicecategory = db.Column(
+        db.String(255),
+        nullable=True,
+        comment='Entra device category / group membership label set at import'
+    )
+
     # Remote access is now modeled per-protocol via the accessmethods
     # relationship (AccessProtocol / ComputerAccess), replacing isvnc/iswinrm.