Remove Codecov integration and add dependency diff workflow

[bartveneman]

Summary

This PR removes the Codecov integration from the build pipeline and build configuration, while adding a new GitHub Actions workflow to track dependency and bundle size changes in pull requests.

Key Changes

• Removed Codecov integration:

  • Deleted the Codecov upload step from the test job in the CI workflow
  • Removed the @codecov/rollup-plugin dependency from package.json
  • Removed Codecov plugin configuration from tsdown.config.ts for both library and CLI builds
  • Removed CODECOV_TOKEN environment variable from the build job

• Updated CI workflow:

  • Renamed the "Build & collect coverage" job to "Build" to reflect its new purpose
  • Removed coverage collection responsibilities from the build step

• Added dependency diff workflow:

  • New dependency-diff job that runs only on pull requests
  • Builds and packs both the source branch and base branch
  • Uses e18e/action-dependency-diff@v1 to compare dependencies and bundle sizes
  • Provides PR comments with dependency and bundle size differences for better visibility into changes

Implementation Details

The new dependency diff workflow:

• Checks out the repository with full history (fetch-depth: 0)
• Builds and packages the current branch
• Checks out the base branch, builds, and packages it
• Compares the two packages to identify dependency and bundle size changes
• Requires read access to contents and write access to pull requests for commenting

https://claude.ai/code/session_01F2YzobfMCLMPh2nhxoW2fn

[github-actions]

⚠️ Duplicate Dependencies (found: 4, threshold: 1)

📦 Package	📋 Versions
@babel/helper-string-parser	2 versions @projectwallace/format-css@3.0.0 @vitest/coverage-v8@4.1.0 magicast@0.5.2 @babel/parser@7.29.0 @babel/types@7.29.0 @babel/helper-string-parser@7.27.1 @projectwallace/format-css@3.0.0 tsdown@0.21.4 ... @babel/parser@8.0.0-rc.2 @babel/types@8.0.0-rc.2 @babel/helper-string-parser@8.0.0-rc.2
@babel/helper-validator-identifier	2 versions @projectwallace/format-css@3.0.0 @vitest/coverage-v8@4.1.0 magicast@0.5.2 @babel/parser@7.29.0 @babel/types@7.29.0 @babel/helper-validator-identifier@7.28.5 @projectwallace/format-css@3.0.0 tsdown@0.21.4 ... @babel/parser@8.0.0-rc.2 @babel/types@8.0.0-rc.2 @babel/helper-validator-identifier@8.0.0-rc.2
@babel/parser	2 versions @projectwallace/format-css@3.0.0 @vitest/coverage-v8@4.1.0 magicast@0.5.2 @babel/parser@7.29.0 @projectwallace/format-css@3.0.0 tsdown@0.21.4 rolldown-plugin-dts@0.22.5 @babel/generator@8.0.0-rc.2 @babel/parser@8.0.0-rc.2
@babel/types	2 versions @projectwallace/format-css@3.0.0 @vitest/coverage-v8@4.1.0 magicast@0.5.2 @babel/parser@7.29.0 @babel/types@7.29.0 @projectwallace/format-css@3.0.0 tsdown@0.21.4 rolldown-plugin-dts@0.22.5 @babel/generator@8.0.0-rc.2 @babel/parser@8.0.0-rc.2 @babel/types@8.0.0-rc.2

💡 To find out what depends on a specific package, run: npm ls example-package

📊 Dependency Size Changes

Note

🎉 This PR removes 24.7 MB of dependencies.

📦 Package	📏 Size
@octokit/openapi-types@24.2.0	-4.6 MB
@octokit/openapi-types@20.0.0	-4.5 MB
zod@3.25.76	-3.6 MB
rollup@4.59.0	-2.8 MB
@codecov/bundler-plugin-core@1.9.1	-2.1 MB
@rollup/rollup-linux-x64-gnu@4.59.0	-2 MB
@octokit/plugin-rest-endpoint-methods@10.4.1	-1.6 MB
undici@5.29.0	-1.2 MB
acorn@8.14.1	-547.5 kB
@octokit/types@13.10.0	-263.7 kB
@octokit/types@12.6.0	-237.9 kB
@octokit/plugin-paginate-rest@9.2.2	-201.7 kB
unplugin@1.16.1	-192.6 kB
@octokit/endpoint@9.0.6	-91.9 kB
@actions/core@1.11.1	-90.9 kB
@fastify/busboy@2.1.1	-80.2 kB
@actions/http-client@2.2.3	-71.2 kB
tunnel@0.0.6	-64.9 kB
@octokit/request@8.4.1	-62.3 kB
@actions/exec@1.1.1	-55.4 kB
@codecov/rollup-plugin@1.9.1	-54.4 kB
@octokit/core@5.2.2	-46.8 kB
webpack-virtual-modules@0.6.2	-46.5 kB
@octokit/graphql@7.1.1	-39.6 kB
@actions/io@1.1.3	-37.1 kB
before-after-hook@2.2.3	-37 kB
chalk@4.1.2	-35 kB
color-convert@2.0.1	-27.2 kB
@octokit/auth-token@4.0.0	-24.2 kB
@actions/github@6.0.1	-23.9 kB
@octokit/request-error@5.1.1	-18.6 kB
ansi-styles@4.3.0	-17 kB
color-name@1.1.4	-6.7 kB
universal-user-agent@6.0.1	-5.8 kB
deprecation@2.3.1	-4 kB
once@1.4.0	Unknown
wrappy@1.0.2	Unknown

Total size change: -24.7 MB