fix(auth,api): resolve SSR vs CSR API URL routing and sanitize ADMIN_TOKEN parsing

- Implement getApiBaseUrl() and getAdminApiBaseUrl() to dynamically distinguish between Server/SSR (process.env.API_BASE_URL) and Client/CSR (process.env.NEXT_PUBLIC_API_BASE_URL)
- Fix missing data on main landing page in containerized environment
- Sanitize and trim ADMIN_TOKEN parsing in Go backend to prevent whitespace/quote mismatch
- Real-time token validation in AdminLayout with auto-redirection on token mismatch
- All unit and E2E test gates passed clean with unanimous PASS reviews

backend/cmd/api/main.go

@@ -4,6 +4,7 @@ import (
 	"encoding/hex"
 	"flag"
 	"log"
+	"strings"
 	"time"
 
 	"git.godopu.com/lab/landing_page/backend/internal/config"
@@ -37,7 +38,7 @@ func main() {
 		cfg.GinMode = *ginModeFlag
 	}
 	if *adminTokenFlag != "" {
-		cfg.AdminToken = *adminTokenFlag
+		cfg.AdminToken = strings.Trim(*adminTokenFlag, " \"'\r\n\t")
 	}
 
 	if cfg.AdminToken == "" {