chore(dev): add web platform dev.yml commands (#158)

### What changes are you making?

Adds platforms/web to the root dev.yml.

`dev up` registers platforms/web under the Node/pnpm bootstrap and runs pnpm install when node_modules is missing.

`dev check` adds `web-lint` (pnpm lint) and `web-test` (pnpm test).

`dev web` commands wrap existing package.json scripts:
Command | Action
-- | --
dev web sample (s) | Start the sample app dev server
dev web build | Build @shopify/checkout-kit to dist/
dev web test | Run unit tests with coverage
dev web test watch | Run tests in watch mode
dev web lint (style) | Typecheck, oxlint, and format check
dev web format (fix) | Auto-fix lint and formatting
dev web clean | Remove dist/ and coverage/

</div></div></div>

### Before you merge

> [!IMPORTANT]
>
> - [ ] I've added tests to support my implementation
> - [ ] I have read and agree with the [Contribution Guidelines](./CONTRIBUTING.md)
> - [ ] I have read and agree with the [Code of Conduct](./CODE_OF_CONDUCT.md)
> - [ ] I've updated the relevant platform README (`platforms/swift/README.md` and/or `platforms/android/README.md`)

---

<details>
<summary>Releasing a new Swift version?</summary>

- [ ] I have bumped the version in `ShopifyCheckoutKit.podspec`
- [ ] I have bumped the version in `platforms/swift/Sources/ShopifyCheckoutKit/ShopifyCheckoutKit.swift`
- [ ] I have updated `platforms/swift/CHANGELOG.md`
- [ ] I have updated the SwiftPM/CocoaPods version snippets in `platforms/swift/README.md` (major version only)

</details>

<details>
<summary>Releasing a new Android version?</summary>

- [ ] I have bumped the `versionName` in `platforms/android/lib/build.gradle`
- [ ] I have updated `platforms/android/CHANGELOG.md`
- [ ] I have updated the Gradle/Maven version snippets in `platforms/android/README.md`

</details>

> [!TIP]
> See the [Contributing documentation](./CONTRIBUTING.md) for the full release process per platform.

Author: toneymathews

dev.yml

@@ -57,10 +57,15 @@ up:
       package_manager: pnpm@10.33.1
       packages:
         - platforms/react-native
+        - platforms/web
   - custom:
       name: Install NPM dependencies (React Native)
       met?: ls -l platforms/react-native | grep node_modules
       meet: cd platforms/react-native && pnpm install
+  - custom:
+      name: Install NPM dependencies (Web)
+      met?: ls -l platforms/web | grep node_modules
+      meet: cd platforms/web && pnpm install
   - custom:
       name: Install gems (React Native sample)
       met?: (cd platforms/react-native/sample/ios && bundle check)
@@ -79,6 +84,8 @@ check:
   react-native-lint-swift: cd platforms/react-native && ./scripts/lint_swift
   react-native-lint-module: cd platforms/react-native && pnpm module lint
   react-native-lint-sample: cd platforms/react-native && pnpm sample lint
+  web-lint: cd platforms/web && pnpm lint
+  web-test: cd platforms/web && pnpm test
 
 commands:
   # Repo-wide
@@ -283,3 +290,37 @@ commands:
         desc: Auto-fix Swift lint and format issues
         aliases: [fix]
         run: cd platforms/react-native && ./scripts/lint_swift fix
+
+  # Web
+  web:
+    desc: "Web Checkout Kit commands"
+    subcommands:
+      sample:
+        desc: Start the sample app dev server
+        aliases: [s]
+        run: cd platforms/web && pnpm sample
+      build:
+        desc: Build the @shopify/checkout-kit package
+        run: cd platforms/web && pnpm build
+      test:
+        desc: Run unit tests with coverage
+        run: cd platforms/web && pnpm test
+        subcommands:
+          watch:
+            desc: Run tests in watch mode
+            run: cd platforms/web && pnpm test:watch
+      lint:
+        desc: Run typecheck, oxlint, and format checks
+        aliases: [style]
+        run: cd platforms/web && pnpm lint
+      format:
+        desc: Auto-fix JS lint and formatting issues
+        aliases: [fix]
+        run: |
+          set -e
+          cd platforms/web
+          pnpm run lint:js:fix
+          pnpm run format
+      clean:
+        desc: Remove dist and coverage directories
+        run: cd platforms/web && pnpm clean