Bump Bun to 1.4 so macOS standalone binaries get a valid code signature (#20578)

## Summary

Fixes #20544.

`bun build --compile` in Bun 1.3.14 writes the ad-hoc Mach-O signature
with the hash of the last 4 KiB page taken over a zero-padded page, not
the real bytes. `codesign --verify` reports an invalid signature, and
macOS 27 checks that page at launch and kills `tailwindcss-macos-arm64`.
Bun 1.4.1 and later sign the real bytes.

This bumps `bun` and `@types/bun` in `@tailwindcss/standalone` from
`^1.3.14` to `^1.4.1`. The lockfile now resolves Bun 1.4.3. The fix
reaches users with the next release, because the binaries are built at
release time.

## Test plan

I built the standalone binaries before and after the bump on Linux (`cd
packages/@tailwindcss-standalone && pnpm build`) and hashed every
4096-byte page of `dist/tailwindcss-macos-arm64` against its
`LC_CODE_SIGNATURE` CodeDirectory:

| | Bun | bad pages | last page hash matches the zero-padded page |
|---|---|---|---|
| `main` | 1.3.14 | `[(17905, 2736)]` | yes |
| this PR | 1.4.3 | none | no |

I could not run the binary on macOS 27, so the launch kill itself is not
tested here.

Also checked with the bump: `pnpm install --frozen-lockfile` passes, the
build finishes for all 7 targets, and the `tailwindcss-linux-x64` binary
builds `@import "tailwindcss"` and generates `.flex`, `.p-4` and
`hover:underline` for a small HTML file.

`dist/tailwindcss-macos-arm64` grows from 73.9 MB to 81.3 MB.

I did not run `integrations/cli/standalone.test.ts`, because it needs
`pnpm pack` tarballs of every package, including the WASM build.

I am new to open source, and this pull request was made with AI
assistance.

---------

Co-authored-by: Robin Malfait <robin.malfait@shopify.com>

Author: i098

CHANGELOG.md

@@ -53,6 +53,7 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 - Don't generate CSS for arbitrary values with unbalanced parentheses or brackets (e.g. `w-[calc(1px]` or `[--x:a[b]`) ([#20577](https://github.com/tailwindlabs/tailwindcss/pull/20577))
 - Canonicalization: prevent `collapse: true` from taking exponentially longer when classes are linked through a utility that sets many properties (e.g. `sr-only`) ([#20558](https://github.com/tailwindlabs/tailwindcss/pull/20558))
 - Ensure `&` is substituted inside `:-moz-any(…)` and `:-webkit-any(…)` in custom variants (e.g. `@custom-variant firefox (:-moz-any(&));`) ([#20486](https://github.com/tailwindlabs/tailwindcss/pull/20486))
+- Ensure the standalone macOS binaries have a valid code signature, so macOS 27 no longer kills them at launch ([#20578](https://github.com/tailwindlabs/tailwindcss/pull/20578))
 
 ## [4.3.3] - 2026-07-16
 

packages/@tailwindcss-standalone/package.json

@@ -42,8 +42,8 @@
     "@parcel/watcher-linux-x64-glibc": "catalog:",
     "@parcel/watcher-linux-x64-musl": "catalog:",
     "@parcel/watcher-win32-x64": "catalog:",
-    "@types/bun": "^1.3.14",
-    "bun": "^1.3.14",
+    "@types/bun": "^1.4.1",
+    "bun": "^1.4.1",
     "lightningcss-darwin-arm64": "catalog:",
     "lightningcss-darwin-x64": "catalog:",
     "lightningcss-linux-arm64-gnu": "catalog:",