feat: fix test collection and add collection stats display

- Fix collect_tests to use JSON report parsing (was returning 0 tests)
- Add Test Collection panel to testing dashboard showing total tests,
  unit/integration/performance breakdown, and file count
- Reorganize sidebar: create Platform Health section with Testing Hub,
  Code Quality, and Background Tasks
- Keep Developer Tools for Components and Icons only
- Platform Monitoring now contains Import Jobs and Application Logs

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

static/admin/js/init-alpine.js

@@ -31,6 +31,7 @@ function data() {
     productCatalog: false,
     contentMgmt: false,
     devTools: false,
+    platformHealth: false,
     monitoring: false,
     settingsSection: false
   };
@@ -73,8 +74,10 @@ function data() {
     // Developer Tools
     components: 'devTools',
     icons: 'devTools',
-    testing: 'devTools',
-    'code-quality': 'devTools',
+    // Platform Health
+    testing: 'platformHealth',
+    'code-quality': 'platformHealth',
+    'background-tasks': 'platformHealth',
     // Platform Monitoring
     imports: 'monitoring',
     logs: 'monitoring',

static/admin/js/testing-dashboard.js

@@ -38,6 +38,12 @@ function testingDashboard() {
             last_run: null,
             last_run_status: null,
             total_test_files: 0,
+            collected_tests: 0,
+            unit_tests: 0,
+            integration_tests: 0,
+            performance_tests: 0,
+            system_tests: 0,
+            last_collected: null,
             trend: [],
             by_category: {},
             top_failing: []