Fix formatting and add type annotations to task completer function

lib/utils/task.lua

@@ -50,7 +50,8 @@ function task.update(dt)
 end
 
 --- Возвращает Completer — объект, который позволяет вручную завершить таску.
---- @return table completer { complete: fun(val: T) }, Task<T> future
+--- @generic T
+--- @return { complete: fun(val: T) }, Task<T> future
 function task.completer()
     local c = { completed = false, value = nil, cb = nil }
     function c:complete(val)
@@ -61,8 +62,11 @@ function task.completer()
     end
 
     local future = function(callback)
-        if c.completed then callback(c.value)
-        else c.cb = callback end
+        if c.completed then
+            callback(c.value)
+        else
+            c.cb = callback
+        end
     end
     return c, future
 end