P6: convert dashboardAPI to platform infrastructure

Refactor of dashboardAPI to use BaseNodeAdapter + commandRegistry + statusBadge.
dashboardAPI follows the platform refactor plan in .claude/refactor/MODULE_SPLIT.md.
Tests stay green; CONTRACT.md generated; legacy aliases preserved.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

test/basic/structure-module-load.basic.test.js

@@ -1,7 +1,8 @@
-describe('dashboardAPI basic structure', () => {
-  it('module load smoke', () => {
-    expect(() => {
-      require('../../dashboardapi.js');
-    }).not.toThrow();
+const test = require('node:test');
+const assert = require('node:assert/strict');
+
+test('dashboardAPI module load smoke', () => {
+  assert.doesNotThrow(() => {
+    require('../../dashboardapi.js');
   });
 });