fix: correct createProcess tuple order in readProcessBytes

createProcess returns (stdin, stdout, stderr, process), not
(stdout, stderr, _, process). Since stdin is Inherited (not CreatePipe),
it returns Nothing, not Just. The pattern (Just outH, Just errH, _, _)
was matching on the stdin and stdout fields, so it always fell through
to the error branch.

src/Roux/Server.hs

@@ -244,8 +244,10 @@ readProcessBytes cmd args = do
                 , std_err = CreatePipe
                 }
     result <- createProcess process
+    -- createProcess returns (stdin, stdout, stderr, process).
+    -- stdin is Inherited → Nothing; stdout/stderr are CreatePipe → Just.
     case result of
-        (Just outH, Just errH, _, ph) -> do
+        (Nothing, Just outH, Just errH, ph) -> do
             hSetBinaryMode outH True
             hSetBinaryMode errH True
             out <- LB.hGetContents outH