refactor(users/glittershark): Rename to grfn

Rename my //users directory and all places that refer to glittershark to
grfn, including nix references and documentation.

This may require some extra attention inside of gerrit's database after
it lands to allow me to actually push things.

Change-Id: I4728b7ec2c60024392c1c1fa6e0d4a59b3e266fa
Reviewed-on: https://cl.tvl.fyi/c/depot/+/2933
Tested-by: BuildkiteCI
Reviewed-by: tazjin <mail@tazj.in>
Reviewed-by: lukegb <lukegb@tvl.fyi>
Reviewed-by: glittershark <grfn@gws.fyi>

users/grfn/xanthous/src/Xanthous/Game/Arbitrary.hs

@@ -0,0 +1,51 @@
+{-# LANGUAGE UndecidableInstances #-}
+{-# OPTIONS_GHC -fno-warn-orphans #-}
+{-# LANGUAGE StandaloneDeriving #-}
+{-# LANGUAGE RecordWildCards #-}
+--------------------------------------------------------------------------------
+module Xanthous.Game.Arbitrary where
+--------------------------------------------------------------------------------
+import           Xanthous.Prelude hiding (foldMap)
+--------------------------------------------------------------------------------
+import           Test.QuickCheck
+import           System.Random
+import           Data.Foldable (foldMap)
+--------------------------------------------------------------------------------
+import           Xanthous.Data.Levels
+import qualified Xanthous.Data.EntityMap as EntityMap
+import           Xanthous.Entities.Entities ()
+import           Xanthous.Entities.Character
+import           Xanthous.Game.State
+import           Xanthous.Orphans ()
+import           Xanthous.Util.QuickCheck (GenericArbitrary(..))
+--------------------------------------------------------------------------------
+
+deriving via GenericArbitrary GameLevel instance Arbitrary GameLevel
+
+instance Arbitrary GameState where
+  arbitrary = do
+    chr <- arbitrary @Character
+    _upStaircasePosition <- arbitrary
+    _messageHistory <- arbitrary
+    levs <- arbitrary @(Levels GameLevel)
+    _levelRevealedPositions <-
+      fmap setFromList
+      . sublistOf
+      . foldMap (EntityMap.positions . _levelEntities)
+      $ levs
+    let (_characterEntityID, _levelEntities) =
+          EntityMap.insertAtReturningID _upStaircasePosition (SomeEntity chr)
+          $ levs ^. current . levelEntities
+        _levels = levs & current .~ GameLevel {..}
+    _randomGen <- mkStdGen <$> arbitrary
+    let _promptState = NoPrompt -- TODO
+    _activePanel <- arbitrary
+    _debugState <- arbitrary
+    let _autocommand = NoAutocommand
+    pure $ GameState {..}
+
+
+instance CoArbitrary GameLevel
+instance Function GameLevel
+instance CoArbitrary GameState
+instance Function GameState