hello-workflow/practice: Workflow file missing the .workflow.cs suffix used everywhere else

Exercise 1 (Hello Workflow), Part A step 2 says to open SayHelloWorkflow.workflow.cs in the Workflow folder, but the file in exercises/hello-workflow/practice/Workflow/ is named SayHelloWorkflow.cs. As a learner working through the .NET course this reads as a missing file or a bad clone, and it can't be resolved by reading the code -- only by guessing that the instructions are wrong.

This looks like a partially applied rename. Commit 391f018 renamed the solution copy to SayHelloWorkflow.workflow.cs but left the practice copy as SayHelloWorkflow.cs. Commit 6400750 later modified both files in a single commit and still left the names mismatched.

It is now the only Workflow file in the repo without the suffix:

Suggested fix:

git mv exercises/hello-workflow/practice/Workflow/SayHelloWorkflow.cs \
       exercises/hello-workflow/practice/Workflow/SayHelloWorkflow.workflow.cs

No .csproj or code changes are needed, since C# does not couple filename to class name and the project globs all .cs files. It also makes the practice/solution diff exactly one line (namespace ...Practice.Workflow vs ...Solution.Workflow), which helps because the exercise instructions tell you to compare against the solution.

Observed at commit 6400750 on main.

Check exercises/hello-workflow/practice/Workflow/SayHelloWorkflow.cs against the corresponding solution file and the Exercise 1, Part A instructions. Rename the practice file to the documented .workflow.cs name, then verify the project still includes it and that the practice/solution comparison matches the stated one-line namespace difference.