fix(common-code): enforce storage policy

TaxBaik.Application/Services/CommonCodeService.cs

@@ -8,6 +8,10 @@ namespace TaxBaik.Application.Services;
 
 public class CommonCodeService(ICommonCodeRepository commonCodeRepository)
 {
+    private const int MaxCodeGroupLength = 80;
+    private const int MaxCodeValueLength = 120;
+    private const int MaxCodeNameLength = 200;
+
     public async Task<IEnumerable<string>> GetAllGroupsAsync(CancellationToken ct = default)
     {
         return await commonCodeRepository.GetAllGroupsAsync(ct);
@@ -36,13 +40,28 @@ public class CommonCodeService(ICommonCodeRepository commonCodeRepository)
 
     public async Task DeleteAsync(string codeGroup, string codeValue, CancellationToken ct = default)
     {
-        await commonCodeRepository.DeleteAsync(codeGroup.Trim(), codeValue.Trim(), ct);
+        await commonCodeRepository.DeleteAsync(NormalizeToken(codeGroup, nameof(codeGroup), MaxCodeGroupLength), NormalizeToken(codeValue, nameof(codeValue), MaxCodeValueLength), ct);
     }
 
     private static void Normalize(CommonCode code)
     {
-        code.CodeGroup = code.CodeGroup.Trim();
-        code.CodeValue = code.CodeValue.Trim();
-        code.CodeName = code.CodeName.Trim();
+        code.CodeGroup = NormalizeToken(code.CodeGroup, nameof(code.CodeGroup), MaxCodeGroupLength);
+        code.CodeValue = NormalizeToken(code.CodeValue, nameof(code.CodeValue), MaxCodeValueLength, disallowWhitespace: true);
+        code.CodeName = NormalizeToken(code.CodeName, nameof(code.CodeName), MaxCodeNameLength);
+    }
+
+    private static string NormalizeToken(string value, string fieldName, int maxLength, bool disallowWhitespace = false)
+    {
+        var normalized = (value ?? string.Empty).Trim();
+        if (string.IsNullOrWhiteSpace(normalized))
+            throw new ValidationException($"{fieldName}은(는) 필수입니다.");
+
+        if (normalized.Length > maxLength)
+            throw new ValidationException($"{fieldName}은(는) 최대 {maxLength}자까지 입력할 수 있습니다.");
+
+        if (disallowWhitespace && normalized.Any(char.IsWhiteSpace))
+            throw new ValidationException($"{fieldName}에는 공백을 사용할 수 없습니다.");
+
+        return normalized;
     }
 }