fix: final review findings

Co-Authored-By: Claude Opus 5.5 <[email protected]>

fsharp/tests/Purity.fs

@@ -29,7 +29,13 @@ let private violations (code: string) =
 
 let private fsFiles () =
     if Directory.Exists srcDir then
-        Directory.GetFiles(srcDir, "*.fs", SearchOption.AllDirectories) |> Array.sort |> List.ofArray
+        Directory.GetFiles(srcDir, "*.fs", SearchOption.AllDirectories)
+        |> Array.filter (fun f ->
+            // skip generated output: any path component named bin or obj
+            let rel = Path.GetRelativePath(srcDir, f)
+            not (rel.Split([| '/'; '\\' |]) |> Array.exists (fun d -> d = "bin" || d = "obj")))
+        |> Array.sort
+        |> List.ofArray
     else
         []