Rewrite existing credits

Each credit has its own draw function

Credits outside of the visible game area are not drawn

modules/dom/canvas.scm

@@ -39,7 +39,8 @@
             translate!
             rotate!
             set-transform!
-            set-image-smoothing-enabled!))
+            set-image-smoothing-enabled!
+            measure-text))
 
 ;; HTMLCanvasElement
 (define-foreign get-context
@@ -98,3 +99,6 @@
 (define-foreign set-image-smoothing-enabled!
   "canvas" "setImageSmoothingEnabled"
   (ref extern) i32 -> none)
+(define-foreign measure-text
+  "canvas" "measureText"
+  (ref extern) (ref string) -> (ref extern))

modules/dom/text-metrics.scm

@@ -0,0 +1,34 @@
+;;; Copyright (C) 2025 Amy Grinn <amy@spritely.institute>
+;;;
+;;; Licensed under the Apache License, Version 2.0 (the "License");
+;;; you may not use this file except in compliance with the License.
+;;; You may obtain a copy of the License at
+;;;
+;;;    http://www.apache.org/licenses/LICENSE-2.0
+;;;
+;;; Unless required by applicable law or agreed to in writing, software
+;;; distributed under the License is distributed on an "AS IS" BASIS,
+;;; WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+;;; See the License for the specific language governing permissions and
+;;; limitations under the License.
+
+;;; Commentary:
+;;;
+;;; HTML canvas TextMetrics interface bindings
+;;;
+;;; Code:
+
+(define-module (dom text-metrics)
+  #:pure
+  #:use-module (scheme base)
+  #:use-module (hoot ffi)
+  #:export (text-metrics-actual-bounding-box-ascent
+            text-metrics-actual-bounding-box-descent))
+
+(define-foreign text-metrics-actual-bounding-box-ascent
+  "textMetrics" "actualBoundingBoxAscent"
+  (ref extern) -> i32)
+
+(define-foreign text-metrics-actual-bounding-box-descent
+  "textMetrics" "actualBoundingBoxDescent"
+  (ref extern) -> i32)

modules/srfi/srf-1.scm

@@ -0,0 +1,3 @@
+(define-module (srfi srfi-1)
+  #:use-module ((scheme base) #:select (fold))
+  #:re-export (fold))