build(deps-dev): bump tsdown from 0.20.3 to 0.21.0

[dependabot]

Bumps tsdown from 0.20.3 to 0.21.0.

Release notes

Sourced from tsdown's releases.

v0.21.0 - Notable Changes

Breaking Changes

Dependency options renamed to deps namespace

The dependency-related options have been moved under a new deps namespace with clearer names:

• external -> deps.neverBundle
• noExternal -> deps.alwaysBundle
• inlineOnly -> deps.onlyAllowBundle
• skipNodeModulesBundle -> deps.skipNodeModulesBundle

Before:

export default defineConfig({
  external: ['vue'],
  noExternal: ['lodash'],
})

After:

export default defineConfig({
  deps: {
    neverBundle: ['vue'],
    alwaysBundle: ['lodash'],
  },
})

The old options still work but are deprecated and will emit warnings.

failOnWarn default changed from 'ci-only' to false

If you relied on the previous behavior where warnings would fail the build in CI environments, you now need to explicitly set failOnWarn: true or failOnWarn: 'ci-only' in your config.

Node.js < 22.18.0 deprecated

tsdown now emits a deprecation warning when running on Node.js versions below 22.18.0. Plan to upgrade your Node.js version accordingly.

New Features

Experimental Node.js SEA executable bundling (exe)

tsdown can now bundle your TypeScript project into a standalone executable using Node.js Single Executable Applications (SEA). A new @tsdown/exe package provides cross-platform executable building support. See the exe documentation for details.

export default defineConfig({
  exe: true, // or { useCodeCache: true, useSnapshot: true }
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Commits

• 5145496 chore: release v0.21.0
• c5db6dc refactor(exe): improve nodeVersion type
• ce7abe9 feat(exe): support latest and latest-lts for nodeVersion
• 944e92a feat: support bundling .node files by default
• 1183ad3 fix(css): remove empty js chunks (#799)
• 0aae946 chore: upgrade rolldown
• 9440739 chore: release v0.21.0-beta.5
• d8a1f5c fix: resolve css files in node_modules (#795)
• 0173c6e feat(exe)!: require Node >=25.7 and default format to esm (#798)
• 288a5f0 feat(css): default css.transformer to lightningcss (#797)
• Additional commits viewable in compare view

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