feat: add comprehensive unit and integration testing infrastructure

- Backend: pytest with unit tests (auth, rbac, config) and integration tests (auth flow, docker, files)
- Frontend: vitest with unit tests (api client) and component tests (login)
- CI: Gitea Actions workflow for automated testing with coverage reports
- Documentation: TESTING.md guide with setup, usage, and best practices
- Coverage goals: 80%+ backend, 70%+ frontend

dashboard/frontend/vitest.config.js

@@ -0,0 +1,21 @@
+import { defineConfig } from 'vitest/config';
+import { svelte } from '@sveltejs/vite-plugin-svelte';
+
+export default defineConfig({
+  plugins: [svelte({ hot: !process.env.VITEST })],
+  test: {
+    globals: true,
+    environment: 'jsdom',
+    setupFiles: ['./tests/setup.js'],
+    coverage: {
+      provider: 'v8',
+      reporter: ['text', 'html', 'lcov'],
+      exclude: ['node_modules/', 'tests/', 'dist/', '*.config.js']
+    }
+  },
+  resolve: {
+    alias: {
+      '@': '/src'
+    }
+  }
+});