fix(ci): add CI stub to security integration tests

Ensure CSRF validation works normally during security API tests.

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Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

tests/int/security-api.int.spec.ts

@@ -7,6 +7,9 @@
 
 import { describe, it, expect, beforeEach, afterEach, vi } from 'vitest'
 import { NextRequest, NextResponse } from 'next/server'
+
+// Clear CI environment variable to ensure CSRF validation works normally during tests
+vi.stubEnv('CI', '')
 import {
   generateTestCsrfToken,
   generateExpiredCsrfToken,