test(e2e): add missing vitest.e2e.config.mts

Create Vitest configuration for end-to-end tests to fix CI e2e-tests workflow.

Configuration:
- Includes only **/*.e2e.test.{mts,ts} files
- Uses 60s timeout for process spawning tests
- Full thread isolation for clean execution
- Same alias resolution as unit tests

Fixes: "Could not resolve vitest.e2e.config.mts" error in CI

Author: jdalton

packages/cli/vitest.e2e.config.mts

@@ -0,0 +1,47 @@
+import os from 'node:os'
+import path from 'node:path'
+import { fileURLToPath } from 'node:url'
+
+import { defineConfig } from 'vitest/config'
+
+import { getLocalPackageAliases } from './scripts/utils/get-local-package-aliases.mjs'
+
+// Get the socket-cli repo root directory.
+const __dirname = path.dirname(fileURLToPath(import.meta.url))
+const repoRoot = path.resolve(__dirname, '../..')
+
+export default defineConfig({
+  resolve: {
+    alias: getLocalPackageAliases(repoRoot),
+    preserveSymlinks: false,
+  },
+  test: {
+    globals: false,
+    environment: 'node',
+    include: [
+      '**/*.e2e.test.{mts,ts}',
+    ],
+    exclude: [
+      '**/node_modules/**',
+      '**/dist/**',
+      '**/.{idea,git,cache,output,temp}/**',
+      '**/{karma,rollup,webpack,vite,vitest,jest,ava,babel,nyc,cypress,tsup,build,eslint,prettier}.config.*',
+    ],
+    reporters: ['default'],
+    setupFiles: ['./test/setup.mts'],
+    // Use threads for better performance.
+    pool: 'threads',
+    poolOptions: {
+      threads: {
+        singleThread: false,
+        maxThreads: os.cpus().length,
+        minThreads: Math.min(4, os.cpus().length),
+        // E2E tests need full isolation for clean execution.
+        isolate: true,
+      },
+    },
+    // E2E tests need longer timeouts for spawning processes.
+    testTimeout: 60_000,
+    hookTimeout: 60_000,
+  },
+})