.NET Framework 4.8 업그레이드 및 WebView2 통합

- 모든 프로젝트를 .NET Framework 4.0 → 4.8로 업그레이드
- WebView2 NuGet 패키지 추가 (v1.0.3537.50)
- 사용자 매뉴얼 폼 추가 (Frm_WebManual)
  * WebView2 컨트롤 통합
  * localhost:58123 자동 로드
  * MDI 메인 메뉴에 Manual 항목 추가

🤖 Generated with [Claude Code](https://claude.com/claude-code)

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

CEnergy/ArinClassV2/CEnergy.vbproj

@@ -36,7 +36,7 @@
     <ApplicationVersion>1.0.0.%2a</ApplicationVersion>
     <UseApplicationTrust>false</UseApplicationTrust>
     <BootstrapperEnabled>true</BootstrapperEnabled>
-    <TargetFrameworkVersion>v4.0</TargetFrameworkVersion>
+    <TargetFrameworkVersion>v4.8</TargetFrameworkVersion>
     <TargetFrameworkProfile />
   </PropertyGroup>
   <PropertyGroup Condition=" '$(Configuration)|$(Platform)' == 'Debug|AnyCPU' ">

CEnergy/ArinClassV2/app.config

@@ -25,4 +25,4 @@
             <!--<add name="EventLog" type="System.Diagnostics.EventLogTraceListener" initializeData="APPLICATION_NAME"/> -->
         </sharedListeners>
     </system.diagnostics>
-<startup><supportedRuntime version="v4.0" sku=".NETFramework,Version=v4.0"/></startup></configuration>
+<startup><supportedRuntime version="v4.0" sku=".NETFramework,Version=v4.8"/></startup></configuration>