fix: disable stdout/stderr buffering for Docker log visibility

app/Main.hs

@@ -8,6 +8,7 @@ module Main (main) where
 import Data.String (fromString)
 import qualified Network.Wai.Handler.Warp as Warp
 import qualified Options.Applicative as Opts
+import System.IO (BufferMode (NoBuffering), hSetBuffering, stderr, stdout)
 
 import qualified Roux
 
@@ -51,6 +52,9 @@ optionsParser =
 
 main :: IO ()
 main = do
+    -- Disable buffering so Docker sees log output immediately.
+    hSetBuffering stdout NoBuffering
+    hSetBuffering stderr NoBuffering
     opts <-
         Opts.execParser $
             Opts.info