chore(test): emit lcov coverage reports

backend/vitest.config.ts

@@ -9,6 +9,7 @@ export default defineConfig({
     hookTimeout: 60000,
     coverage: {
       provider: 'v8',
+      reporter: ['text', 'lcov'],
       include: ['src/**/*.ts'],
       exclude: ['src/server.ts', 'src/scripts/**', 'src/types/**', 'src/config/logger.ts'],
       thresholds: {

frontend/vite.config.ts

@@ -21,6 +21,7 @@ export default defineConfig({
     css: false,
     coverage: {
       provider: 'v8',
+      reporter: ['text', 'lcov'],
       // Business logic modules — the threshold applies to included files.
       include: [
         'src/lib/**/*.{ts,tsx}',