feat(dev_tools): add diagnostics hub with permissions audit tool

Evolve the platform-debug page into a diagnostics hub with sidebar
explorer layout. Add permissions audit API that introspects all
registered page routes and reports auth/permission enforcement status.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

app/modules/dev_tools/locales/en.json

@@ -14,9 +14,20 @@
         "components": "Components",
         "icons": "Icons",
         "sql_query": "SQL Query",
-        "platform_debug": "Platform Debug",
+        "diagnostics": "Diagnostics",
         "translation_editor": "Translation Editor"
     },
+    "diagnostics": {
+        "title": "Diagnostics",
+        "platform_trace": "Platform Trace",
+        "permissions_audit": "Permissions Audit",
+        "run_audit": "Run Audit",
+        "status_ok": "OK",
+        "status_warning": "Warning",
+        "status_error": "Error",
+        "total_routes": "Total Routes",
+        "no_routes_match": "No routes match your filters"
+    },
     "translation_editor": {
         "title": "Translation Editor",
         "all_modules": "All Modules",