refactor: convert solution to .slnx format and move to src/ (#29)

Converts from legacy .sln format to the new XML-based .slnx format.
Moves solution file from root to src/ for consistency with other repos.
Updates CI workflow to reference the new solution path.

Author: CalvinAllen

.github/workflows/ci.yml

@@ -5,13 +5,11 @@ on:
     branches: [main]
     paths:
       - 'src/**'
-      - '*.sln'
       - '.github/workflows/ci.yml'
   pull_request:
     branches: [main]
     paths:
       - 'src/**'
-      - '*.sln'
       - '.github/workflows/ci.yml'
 
 jobs:
@@ -33,10 +31,10 @@ jobs:
           dotnet-version: '10.0.x'
 
       - name: Restore dependencies
-        run: dotnet restore CodingWithCalvin.VSToolbox.sln
+        run: dotnet restore src/CodingWithCalvin.VSToolbox.slnx
 
       - name: Build
-        run: dotnet build CodingWithCalvin.VSToolbox.sln --configuration ${{ matrix.configuration }} -p:Platform=${{ matrix.platform }} --no-restore
+        run: dotnet build src/CodingWithCalvin.VSToolbox.slnx --configuration ${{ matrix.configuration }} -p:Platform=${{ matrix.platform }} --no-restore
 
       - name: Test
-        run: dotnet test CodingWithCalvin.VSToolbox.sln --configuration ${{ matrix.configuration }} -p:Platform=${{ matrix.platform }} --no-build --verbosity normal
+        run: dotnet test src/CodingWithCalvin.VSToolbox.slnx --configuration ${{ matrix.configuration }} -p:Platform=${{ matrix.platform }} --no-build --verbosity normal

CodingWithCalvin.VSToolbox.sln

@@ -0,0 +1,13 @@
+<Solution>
+  <Configurations>
+    <Configuration Name="Debug" />
+    <Configuration Name="Release" />
+    <Platform Name="Any CPU" />
+    <Platform Name="x64" />
+    <Platform Name="x86" />
+  </Configurations>
+  <Folder Name="/src/">
+    <Project Path="CodingWithCalvin.VSToolbox/CodingWithCalvin.VSToolbox.csproj" />
+    <Project Path="CodingWithCalvin.VSToolbox.Core/CodingWithCalvin.VSToolbox.Core.csproj" />
+  </Folder>
+</Solution>