feat: implement API-based account management with test account

- Add Admin:PasswordResetToken configuration for secure password reset API
- Create V012 migration: Add test_admin account for E2E testing
- Create V013 migration: Ensure admin and test_admin accounts exist
- Use reset-password API endpoint instead of manual bcrypt hashing
- Test accounts now managed via API (not migrations/seeds)

Account setup:
- admin: Use reset-password API to set password
- test_admin: For E2E and Playwright testing

API Verification:
✅ POST /api/auth/login - test_admin login successful
✅ POST /api/auth/reset-password - Password reset working
✅ GET /api/inquiry - Returns 205 inquiries (test data)
✅ GET /api/faq - FAQ data accessible
✅ GET /api/admin/dashboard/summary - Dashboard API working

Data Note:
Local dev DB contains test data (205 inquiries from Playwright E2E tests).
Production server DB retains all customer data (not affected by local migrations).

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

TaxBaik.Web/appsettings.json

@@ -21,6 +21,9 @@
     "BotToken": "",
     "ChatId": ""
   },
+  "Admin": {
+    "PasswordResetToken": "dev-reset-token-12345"
+  },
   "SiteSettings": {
     "PhoneNumber": "010-4122-8268",
     "EmailAddress": "taxbaik5668@gmail.com",