Improve branch sync workflow, migrate to slnx, and clean up repo

.gitignore

@@ -31,3 +31,14 @@ msbuild.err
 msbuild.wrn
 .vs/
 .idea/
+
+# SQLite database files
+*.db
+*.db-shm
+*.db-wal
+
+# Source generator temp output
+tmpgen/
+
+# ReSharper/Rider user settings
+*.DotSettings.user

.sync-exclude

@@ -0,0 +1,12 @@
+# Files that must remain version-specific per target branch.
+# These are reset to the target branch version after cherry-picking from main.
+#
+# Reason: EF Core 10 introduced UpdateSettersBuilder<T> and IDbContextOptionsConfiguration<T>
+# which don't exist in EF Core 8/9. These files use different APIs per version.
+
+src/TickerQ.EntityFrameworkCore/Infrastructure/MappingExtensions.cs
+src/TickerQ.EntityFrameworkCore/Infrastructure/BasePersistenceProvider.cs
+src/TickerQ.EntityFrameworkCore/Infrastructure/TickerQueryExtensions.cs
+
+# Solution file — main uses .slnx (net10+), older branches use .sln
+TickerQ.sln

TickerQ.slnx

@@ -0,0 +1,37 @@
+<Solution>
+  <Configurations>
+    <Platform Name="Any CPU" />
+    <Platform Name="x64" />
+    <Platform Name="x86" />
+  </Configurations>
+  <Folder Name="/.Solution Items/">
+    <File Path="Directory.Build.props" />
+  </Folder>
+  <Folder Name="/.Solution Items/workflows/">
+    <File Path=".github/workflows/build.yml" />
+    <File Path=".github/workflows/pr.yaml" />
+    <File Path=".github/workflows/publish.yml" />
+  </Folder>
+  <Folder Name="/samples/">
+    <Project Path="samples/TickerQ.Sample.ApplicationDbContext/TickerQ.Sample.ApplicationDbContext.csproj" />
+    <Project Path="samples/TickerQ.Sample.Console/TickerQ.Sample.Console.csproj" />
+    <Project Path="samples/TickerQ.Sample.WebApi/TickerQ.Sample.WebApi.csproj" />
+    <Project Path="samples/TickerQ.Sample.WorkerService/TickerQ.Sample.WorkerService.csproj" />
+  </Folder>
+  <Folder Name="/src/">
+    <File Path="src/Directory.Build.props" />
+    <Project Path="src/TickerQ.Caching.StackExchangeRedis/TickerQ.Caching.StackExchangeRedis.csproj" />
+    <Project Path="src/TickerQ.Dashboard/TickerQ.Dashboard.csproj" />
+    <Project Path="src/TickerQ.EntityFrameworkCore/TickerQ.EntityFrameworkCore.csproj" />
+    <Project Path="src/TickerQ.Instrumentation.OpenTelemetry/TickerQ.Instrumentation.OpenTelemetry.csproj" />
+    <Project Path="src/TickerQ.RemoteExecutor/TickerQ.RemoteExecutor.csproj" />
+    <Project Path="src/TickerQ.SDK/TickerQ.SDK.csproj" />
+    <Project Path="src/TickerQ.SourceGenerator/TickerQ.SourceGenerator.csproj" />
+    <Project Path="src/TickerQ.Utilities/TickerQ.Utilities.csproj" />
+    <Project Path="src/TickerQ/TickerQ.csproj" />
+  </Folder>
+  <Folder Name="/tests/">
+    <Project Path="tests/TickerQ.EntityFrameworkCore.Tests/TickerQ.EntityFrameworkCore.Tests.csproj" />
+    <Project Path="tests/TickerQ.Tests/TickerQ.Tests.csproj" />
+  </Folder>
+</Solution>