ci: enhanced CI/CD and test coverage

- Update version from 0.2.0 to 0.9.0
- Upgrade Vitest from v3 to v4 for improved testing capabilities
- Add @vitest/coverage-v8 for comprehensive code coverage reporting
- Enhance GitHub Actions CI workflow with separate unit and integration
test runs
- Integrate Codecov v5 for coverage reporting and test results tracking
- Add JUnit reporter for better test result analysis
- Configure @codecov/vite-plugin for automated coverage collection

vitest.config.ts

@@ -1,11 +1,32 @@
 import { defineConfig } from "vitest/config";
+import { codecovVitePlugin } from "@codecov/vite-plugin";
 import path from "path";
 
 export default defineConfig({
+	plugins: [
+		codecovVitePlugin({
+			enableBundleAnalysis: process.env.CODECOV_TOKEN !== undefined,
+			bundleName: "rdap",
+			uploadToken: process.env.CODECOV_TOKEN,
+		}),
+	],
 	test: {
 		globals: true,
 		environment: "happy-dom",
 		setupFiles: ["./src/test/setup.ts"],
+		coverage: {
+			provider: "v8",
+			reporter: ["text", "json", "html", "lcov"],
+			exclude: [
+				"**/*.config.*",
+				"**/dist/**",
+				"**/node_modules/**",
+				"**/.next/**",
+				"**/test/**",
+				"**/*.test.{ts,tsx}",
+				"**/src/env/**",
+			],
+		},
 	},
 	resolve: {
 		alias: {