[App Router] redirect() causes the target page to be server-rendered twice when navigated via <Link>

### Link to the code that reproduces this issue https://github.com/lp0ql/next-15.3.1-double-server-side-rendering ### To Reproduce ### Describe the Bug When a user clicks a <Link> (next/link) that points to a route where the server component calls redirect(), the *target* page appears to be server-rendered **twice**. - **Does _not_ happen in v14** (tested with 14.2.28). - **Does _not_ happen in production** (npm run build && npm run start). - **Does _not_ happen when reactStrictMode is false** in next.config.js ### Steps to Reproduce The [repository](https://github.com/lp0ql/next-15.3.1-double-server-side-rendering) contains three sub-directories: | Directory | Next.js version | Purpose | |-----------|-----------------|---------| | **15** | 15.3.1 | A Next.js app that **contains an in-app explanation of the issue and links that trigger the bug**. It also includes a scenario that mimics a real-world use case, so you can reproduce the problem while reading the description. | | **14** | 14.2.28 | Identical to **15** except that it uses **Next.js 14**. Running this directory shows that the bug does **not** occur in v14. | | **15-reproduction-template** | 15.x(canary) | The structure follows the official “reproduction-template” starter used in Next.js issues. | To verify the regression: 1. `git clone https://github.com/lp0ql/next-15.3.1-double-server-side-rendering` 2. `cd next-15.3.1-double-server-side-rendering/15` or `cd next-15.3.1-double-server-side-rendering/15-reproduction-template` 3. `npm install` 4. `npm run dev` 5. Open <http://localhost:3000> 6. Click link 7. Watch the dev-server terminal — you should see the same log line appear twice. If you repeat the same procedure inside the **14** directory, the log appears only **once**, confirming that this is a v15-specific regression. ### Current vs. Expected behavior | Current | Expected | | ----- | ----- | | // click next link <br /> MinimumSetup <br /> Minimum Setup Result <br /> Minimum Setup Result |…