feat: web dashboard and playground work

The NexusDashboard-parity dashboard (dDashboardServer) and everything built on it on the experimental branch:
accounts, characters, properties and moderation tools, permissions shared with in-game slash commands, economy
reports, World 3D and property 3D views with client scenery, scheduled events (features, vanity changes, live
events, announcements, restarts), vanity files and events, the CDClient browser, the message inspector with saved
captures, chat filter tools, community challenges, live ops, the AI moderator helper, and the server-side changes
they need.

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

.github/workflows/dashboard-smoke.yml

@@ -0,0 +1,38 @@
+name: Dashboard smoke test
+
+# Starts the whole server on an empty database and checks the web dashboard (tests/smoke/dashboard_smoke_test.py).
+# The servers need a LEGO Universe client, which can't be shipped with the repository, so this runs on a self-hosted
+# runner that has one. To turn it on, set these repository variables (Settings > Secrets and variables > Actions):
+#   DLU_SMOKE_RUNNER    the runner label, e.g. dlu-client
+#   DLU_CLIENT_LOCATION the client folder on that runner (the one with res/)
+# Pull requests from forks never run here: their code would run on your machine.
+
+on:
+  workflow_dispatch:
+  pull_request:
+    branches: [ main ]
+
+jobs:
+  smoke:
+    if: >-
+      vars.DLU_SMOKE_RUNNER != '' &&
+      (github.event_name == 'workflow_dispatch' || github.event.pull_request.head.repo.full_name == github.repository)
+    runs-on: [ self-hosted, "${{ vars.DLU_SMOKE_RUNNER }}" ]
+    timeout-minutes: 60
+    steps:
+    - uses: actions/checkout@de0fac2e4500dabe0009e67214ff5f5447ce83dd # v6.0.2
+      with:
+        submodules: true
+    - name: Configure
+      run: cmake -S . -B build -DCMAKE_BUILD_TYPE=RelWithDebInfo
+    - name: Build
+      run: cmake --build build --parallel
+    - name: Unit tests
+      run: ctest --test-dir build --output-on-failure
+    - name: Smoke test
+      env:
+        CLIENT_LOCATION: ${{ vars.DLU_CLIENT_LOCATION }}
+      run: python3 tests/smoke/dashboard_smoke_test.py --build build --fresh --keep
+    - name: Server logs
+      if: failure()
+      run: find /tmp -maxdepth 2 -path '/tmp/dlu-smoke-*/server.log' -exec tail -n 200 {} \;