fix: save recipe images to recipe-images/ subdirectory

Previously images were saved directly in the recipe directory
alongside .cook files. Now they go into <recipes-dir>/recipe-images/,
keeping the recipe directory clean and making the purpose of the
file clear from its path.

src/Roux/Server.hs

@@ -678,10 +678,13 @@ uploadImageHandler recipeDir _state request respond =
                                         (\c -> if isAlphaNum c || c == '.' || c == '-' || c == '_' then c else '_')
                                         (T.unpack basename <> if null ext then ".jpg" else ext)
                                 imageFilename = T.pack safeName
-                                filepath = recipeDir </> safeName
+                                imagesDir = recipeDir </> "recipe-images"
+                                filepath = imagesDir </> safeName
                             case decode (TE.encodeUtf8 fileB64) of
                                 Left err -> respond (jsonError ("Base64 decode failed: " <> T.pack err))
                                 Right content -> do
+                                    -- Ensure the recipe-images directory exists
+                                    createDirectoryIfMissing True imagesDir
                                     -- Save the image file
                                     BS.writeFile filepath content
                                     putStrLn $ "[roux] saved recipe image to " <> filepath
@@ -705,7 +708,7 @@ serveRecipeImage recipeDir filename _request respond = do
     if ext `notElem` [".jpg", ".jpeg", ".png", ".gif", ".webp"]
         then respond notFound
         else do
-            let filepath = recipeDir </> filename
+            let filepath = recipeDir </> "recipe-images" </> filename
             exists <- doesFileExist filepath
             if not exists
                 then respond notFound