Error when reloading dynamically registered content script

Describe the bug

An error occurs in development when reloading a dynamically registered content script.

It can be worked around by including the matches property in the content script entrypoint (see the included reproduction code).

I'd be happy to do a PR if a solution is agreed.

Reproduction

wxt-content-script-reload-bug.zip

Steps to reproduce

Launch the provided project and look at the service worker logs. Editing the content script in dev causes the error to appear again in the service worker.

System Info

System:
    OS: macOS 15.4.1
    CPU: (10) arm64 Apple M1 Max
    Memory: 254.25 MB / 64.00 GB
    Shell: 5.9 - /bin/zsh
  Binaries:
    Node: 22.14.0 - ~/.nodenv/versions/22/bin/node
    Yarn: 1.22.22 - ~/.nodenv/versions/22/bin/yarn
    npm: 11.2.0 - ~/.nodenv/versions/22/bin/npm
    pnpm: 10.11.0 - ~/.nodenv/versions/22/bin/pnpm
  Browsers:
    Brave Browser: 135.1.77.100
    Chrome: 136.0.7103.114
    Chrome Canary: 138.0.7181.0
    Edge: 136.0.3240.76
    Safari: 18.4
    Safari Technology Preview: 18.4
  npmPackages:
    wxt: ^0.20.6 => 0.20.6

Used Package Manager

pnpm

Validations

• Read the Contributing Guidelines.
• Read the docs.
• Check that there isn't already an issue that reports the same bug to avoid creating a duplicate.
• Check that this is a concrete bug. For Q&A open a GitHub Discussion or join our Discord Chat Server.
• The provided reproduction is a minimal reproducible example of the bug.

Launch the attached wxt-content-script-reload-bug.zip reproduction with pnpm and inspect the service worker logs while editing the dynamically registered content script. Trace the development reload path and use the reproduction steps to verify that reloading no longer produces the reported error without requiring matches in the entrypoint.