test: add @vitest/coverage-v8 + test:coverage to all workspaces

apps/api/package.json

@@ -8,6 +8,7 @@
     "start": "tsx src/index.ts",
     "test": "vitest run",
     "test:watch": "vitest",
+    "test:coverage": "vitest run --coverage",
     "typecheck": "tsc --noEmit",
     "db:generate": "drizzle-kit generate",
     "db:migrate": "tsx src/db/migrate.ts",
@@ -23,6 +24,7 @@
     "zod": "^3.23.8"
   },
   "devDependencies": {
+    "@vitest/coverage-v8": "^3",
     "drizzle-kit": "^0.30.1",
     "tsx": "^4.19.2",
     "typescript": "^5.7.2",

apps/api/vitest.config.ts

@@ -5,5 +5,13 @@ export default defineConfig({
     environment: 'node',
     setupFiles: ['./test/setup.ts'],
     fileParallelism: false,
+    coverage: {
+      provider: 'v8',
+      all: true,
+      reporter: ['text', 'json-summary'],
+      include: ['src/**'],
+      // Generated / non-logic files: excluded with intent (not silent gaps).
+      exclude: ['src/db/schema.ts', 'src/index.ts', '**/*.d.ts'],
+    },
   },
 });