Extract programmatic pan coord calculations into gameboard module

package-lock.json

@@ -5,7 +5,7 @@
   "packages": {
     "": {
       "dependencies": {
-        "pan-zoom": "github:webdevcat-me/pan-zoom"
+        "pan-zoom": "file:../pan-zoom"
       },
       "devDependencies": {
         "esbuild": "^0.20.2",
@@ -16,6 +16,13 @@
         "selenium-webdriver": "^4.19.0"
       }
     },
+    "../pan-zoom": {
+      "version": "0.2.0",
+      "devDependencies": {
+        "esbuild": "^0.20.2",
+        "esbuild-server": "^0.3.0"
+      }
+    },
     "node_modules/@ampproject/remapping": {
       "version": "2.3.0",
       "resolved": "https://registry.npmjs.org/@ampproject/remapping/-/remapping-2.3.0.tgz",
@@ -3819,8 +3826,8 @@
       "dev": true
     },
     "node_modules/pan-zoom": {
-      "version": "0.2.0",
-      "resolved": "git+ssh://git@github.com/webdevcat-me/pan-zoom.git#9c34e15c47cf3578adeff41693a62061a25fdcde"
+      "resolved": "../pan-zoom",
+      "link": true
     },
     "node_modules/parent-module": {
       "version": "1.0.1",