bug: Try.Run throws when the caught exception's Message is whitespace

[Chris-Wolfgang]

Symptom

Discovered by FsCheck fuzz property Fuzz_Try_Run_of_throwing_action_carries_message in the #170 batch:

Falsifiable, after 19 tests (0 shrinks):
---- System.ArgumentException : errorMessage cannot be null, empty, or whitespace. (Parameter 'errorMessage')

Repro

Result r = Try.Run(() => throw new InvalidOperationException(" "));
// throws System.ArgumentException instead of returning r.Failed == true

Cause

Try.Run(Action) (src/Wolfgang.TryPattern/Try.cs) catches every Exception and calls Result.Failure(ex.Message). Result.Failure (src/Wolfgang.TryPattern/Result.cs) requires a non-null, non-empty, non-whitespace error message and throws ArgumentException otherwise.

An exception whose Message is whitespace-only (or empty) makes Try.Run itself throw — defeating the whole point of the wrapper. Same failure mode applies to Try.Run<T>, Try.RunAsync, Try.RunAsync<T>.

Suggested fix

In the catch inside every Try.Run* overload, defensively coerce a whitespace / empty / null exception message to a fallback string before handing it to Result.Failure. Candidates:

• ex.GetType().Name (e.g. "InvalidOperationException").
• "<exception message was empty or whitespace>".

Scope note

This is exactly the class of edge-case the #170 fuzz workflow was designed to surface. The tightened property in that PR uses a generator that excludes whitespace so the fuzz suite ships clean while this bug is fixed separately.