Build: Windows Portable-Build (§30.2) + Frontend-Tests (§17.10)

- build_portable.sh: Nuitka Onefolder (ADR-0005), 5 Schritte:
  uv sync -> Frontend -> Rust (cargo optional) -> Nuitka ->
  GStreamer-Buendelung + portable Struktur + SHA-256 + ZIP
- Portable Struktur (§9): PORTABLE_MODE, runtime/gstreamer, web/,
  plugins/, projects/, media/, userdata/, config/, logs/, licenses/
- Frontend-Tests: Vitest + Testing Library, 9 Tests:
  LayerTable (10 Spalten, Selektion, 7 Zustaende, Screen-Reader),
  StatusBar (FPS 2 Dezimalstellen, Quality Auto, Art-Net-Status)
- Gesamtsuite 595 Python + 9 Vitest gruen

apps/web/vitest.config.ts

@@ -0,0 +1,11 @@
+import { defineConfig } from 'vitest/config';
+import react from '@vitejs/plugin-react';
+
+export default defineConfig({
+  plugins: [react()],
+  test: {
+    environment: 'jsdom',
+    globals: false,
+    setupFiles: ['./src/test/setup.ts'],
+  },
+});