fix: add static file serving with custom middleware

- Replaced wai-app-static with lightweight inline static file server
- Static files served from frontend/static/ under /static/ path
- Fixed ByteString/FilePath type mismatches for GHC 9.10
- Verified: CSS, manifest, login, signup, dashboard all HTTP 200

src/Sis/Page/Login.hs

@@ -1,12 +1,21 @@
-{-# LANGUAGE FlexibleContexts, DeriveAnyClass, DeriveGeneric, MultiParamTypeClasses, FlexibleInstances, UndecidableInstances, TypeApplications, TypeOperators, OverloadedStrings #-}
+{-# LANGUAGE DeriveAnyClass #-}
+{-# LANGUAGE DeriveGeneric #-}
+{-# LANGUAGE FlexibleContexts #-}
+{-# LANGUAGE FlexibleInstances #-}
+{-# LANGUAGE MultiParamTypeClasses #-}
+{-# LANGUAGE OverloadedStrings #-}
+{-# LANGUAGE TypeApplications #-}
+{-# LANGUAGE TypeOperators #-}
+{-# LANGUAGE UndecidableInstances #-}
 {-# OPTIONS_GHC -Wno-unused-imports -Wno-unused-do-bind -Wno-redundant-constraints #-}
 
 module Sis.Page.Login (page) where
-import Effectful
+
 import Data.Text (Text)
 import Data.Text qualified as T
+import Effectful
+import Sis.Auth (generateToken, hashPassword, verifyPassword)
 import Sis.Database
-import Sis.Auth (hashPassword, verifyPassword, generateToken)
 import Sis.Route
 import Sis.Style
 import Sis.Types
@@ -15,6 +24,7 @@ import Web.Hyperbole
 import Web.Hyperbole.Effect.Session
 import Web.Hyperbole.HyperView.Forms
 import Web.Hyperbole.Page
+
 data LoginPage = LoginPage
     deriving stock (Generic)
     deriving anyclass (ViewId)