dx build / dx serve can stall on macOS arm64 when automatic Tailwind is enabled

Hi team — thank you for maintaining Dioxus.

**Problem**

On macOS arm64, dx build / dx serve can stall when automatic Tailwind integration is enabled.

In the repro, the last visible log line is where dx spawns the managed Tailwind binary for the default root-level tailwind.css. After that, the build does not continue into the normal Cargo/WebAssembly build flow.

I reproduced this with a fresh app outside the Dioxus monorepo as well, so it does not appear to depend on the Dioxus workspace itself.

I have only reproduced this on macOS arm64 so far.

**Steps To Reproduce**

Create a fresh Dioxus app with Tailwind enabled.
From the project root, run dx build --platform web --verbose or dx serve --platform web --verbose.
Observe that the last visible log line is the Tailwind spawn, and the build does not continue.
Example last log line:
```text
0.290s DEBUG dx::tailwind: Spawning tailwindcss@v4.1.5 with args: ["~/.dx/tailwind/tailwindcss-v4.1.5", "--input", "/tailwind.css", "--output", "/assets/tailwind.css", "--watch"]
```
**Expected behavior**

dx should run the automatic Tailwind step and then continue into the normal web build process.

**Screenshots**

Not included. The most relevant artifact is the verbose log output above.

**Environment:**
```text
Dioxus version: 0.7.3
Rust version: rustc 1.93.1 (01f6ddf75 2026-02-11)
OS info: macOS arm64
App platform: web
```
**Questionnaire**

I would like to help fix the macOS case.