Keep manual quantity in editor group-delete snapshots

The editor built the circuit-group subtree snapshot without
manualQuantity, while the server compares it with an exact capture that
includes the column. Deleting any group that contained a device row was
therefore rejected with "Circuit-group subtree changed before deletion."

The new integration test builds the snapshot from the real circuit-tree
read model, as the editor does, and deletes the group for a manual row
and for a row with a Revit quantity share.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

tests/circuit-group-numbering.test.ts

@@ -354,7 +354,7 @@ describe("circuit group numbering", () => {
               displayName: "Leuchte Flur",
               phaseType: "single_phase",
               quantity: 2,
-              manualQuantity: 2,
+              manualQuantity: 1,
               powerPerUnit: 0.05,
               simultaneityFactor: 1,
               cosPhi: 0.95,
@@ -380,6 +380,10 @@ describe("circuit group numbering", () => {
         .linkedProjectDeviceId,
       "device-1"
     );
+    assert.equal(
+      snapshot.circuits[0].circuit.deviceRows[0].manualQuantity,
+      1
+    );
     assert.equal(
       snapshot.circuits[0].circuit.deviceRows[0]
         .overriddenFields,