Add atomic circuit update commands

tests/project-command.model.test.ts

@@ -5,6 +5,10 @@ import {
   serializeProjectCommand,
   type SerializedProjectCommand,
 } from "../src/domain/models/project-command.model.js";
+import {
+  assertCircuitUpdateProjectCommand,
+  createCircuitUpdateProjectCommand,
+} from "../src/domain/models/circuit-project-command.model.js";
 
 describe("serialized project commands", () => {
   it("round-trips a versioned command envelope", () => {
@@ -72,3 +76,49 @@ describe("serialized project commands", () => {
     );
   });
 });
+
+describe("circuit update project commands", () => {
+  it("creates a typed command with explicit null clearing semantics", () => {
+    const command = createCircuitUpdateProjectCommand("circuit-1", {
+      displayName: null,
+      cableLength: 12.5,
+      isReserve: false,
+    });
+
+    assert.doesNotThrow(() => assertCircuitUpdateProjectCommand(command));
+    assert.deepEqual(command.payload.changes, [
+      { field: "displayName", value: null },
+      { field: "cableLength", value: 12.5 },
+      { field: "isReserve", value: false },
+    ]);
+  });
+
+  it("rejects empty, duplicate and invalid field changes", () => {
+    assert.throws(
+      () => createCircuitUpdateProjectCommand("circuit-1", {}),
+      /at least one change/
+    );
+    assert.throws(
+      () =>
+        assertCircuitUpdateProjectCommand({
+          schemaVersion: 1,
+          type: "circuit.update",
+          payload: {
+            circuitId: "circuit-1",
+            changes: [
+              { field: "displayName", value: "A" },
+              { field: "displayName", value: "B" },
+            ],
+          },
+        }),
+      /duplicate field/
+    );
+    assert.throws(
+      () =>
+        createCircuitUpdateProjectCommand("circuit-1", {
+          voltage: 0,
+        }),
+      /outside its allowed range/
+    );
+  });
+});