Exclude stories from the published build

They were compiled into dist despite not being exported, dragging their
base64-js import in as a runtime dependency; it is now dev-only. The
build uses a new tsconfig.build.json while tsconfig.json still covers
everything for the editor and the new typecheck script in ci, so the
stories remain typechecked (Storybook's own build only transpiles).

Author: microbit-matt-hillsdon

package-lock.json

@@ -57,11 +57,12 @@
   },
   "scripts": {
     "dev": "vite",
-    "build:esm": "tsc -p tsconfig.json && echo '{\"type\": \"module\"}' > dist/esm/package.json",
+    "build:esm": "tsc -p tsconfig.build.json && echo '{\"type\": \"module\"}' > dist/esm/package.json",
     "build:cjs": "tsc -p tsconfig.cjs.json && echo '{\"type\": \"commonjs\"}' > dist/cjs/package.json",
     "build": "npm run build:esm && npm run build:cjs",
+    "typecheck": "tsc -p tsconfig.json --noEmit",
     "lint": "eslint . --ext ts,tsx --report-unused-disable-directives --max-warnings 0",
-    "ci": "npm run lint && npm run build && npm run build:storybook",
+    "ci": "npm run lint && npm run typecheck && npm run build && npm run build:storybook",
     "storybook": "storybook dev -p 6006",
     "build:storybook": "storybook build",
     "docs": "typedoc"
@@ -70,11 +71,9 @@
     "react": ">=18.0.0",
     "react-dom": ">=18.0.0"
   },
-  "dependencies": {
-    "base64-js": "^1.5.1"
-  },
   "devDependencies": {
     "@chromatic-com/storybook": "^1.2.25",
+    "base64-js": "^1.5.1",
     "@storybook/addon-essentials": "^8.0.5",
     "@storybook/addon-interactions": "^8.0.5",
     "@storybook/addon-links": "^8.0.5",

package.json

@@ -0,0 +1,4 @@
+{
+  "extends": "./tsconfig.json",
+  "exclude": ["src/stories"]
+}

tsconfig.build.json

@@ -1,5 +1,5 @@
 {
-  "extends": "./tsconfig.json",
+  "extends": "./tsconfig.build.json",
   "compilerOptions": {
     "module": "CommonJS",
     "moduleResolution": "Node",