zip.includeSources does not behave intuitively, can lead to data leak

Describe the bug

Setup

// wxt.config.ts
export default defineConfig({
  zip: {
    includeSources: ['entrypoints/**'],
  },
})

Repo tree:

entrypoints/foo.ts
entrypoints/bar.js
cache/secrets/abc
super-secret-file
.gitignore

Expected behavior

$ wxt zip:firefox
$ zipinfo .output/*sources.zip
entrypoints/foo.ts
entrypoints/bar.js

Current non-intuitive, dangerously leaky behavior

$ wxt zip:firefox
$ zipinfo .output/*sources.zip
entrypoints/foo.ts
entrypoints/bar.js
cache/secrets/abc
super-secret-file

Hacky workaroud

I should not have to do this, but that's how I worked around this bug:

export default defineConfig({
  zip: {
    excludeSources: ['**'],
    includeSources: ['entrypoints/**'],
  },
})

I'll point out that this usually not how an allowlist/denylist behaves. The "accepted", safe, intuitive behavior is the following:

• Nothing configured: default behavior, today "Hidden files, node_modules, and tests are ignored". I'd personally vote for a more advanced "respect .Xignore" support for a bunch of popular VCSes, like what ripgrep does, but that's a stretch.
• Only allowlist provided (include): takes precedence since the user went through the trouble of customizing this setting; only what's "included" is included; not what happens, and what this bug is about.
• Only denlist provided (exclude): takes precedence, everything is included except what's denied.
• Both allowlist & denylist provided: only what passes the allowlist, then filter out further according to denylist. Though I accept that the opposite (first denylist, then force-allowlist), which is WXT's current behavior ("[includeSources] overrides excludeSources; if a file matches both lists, it is included in the ZIP") is acceptable albeit annoying.

Pointers:

• https://wxt.dev/guide/essentials/publishing.html#firefox-addon-store
• https://wxt.dev/api/reference/wxt/interfaces/InlineConfig.html#zip
• Vaguely related: #1505

Reproduction

repro.zip

Steps to reproduce

$ mkdir /tmp/repro && cd /tmp/repro
$ unzip /tmp/repro.zip
$ npm install
$ npm run zip:firefox
$ zipinfo .output/*sources.zip

System Info

System:
    OS: Linux 6.18 cpe:/o:nixos:nixos:26.05 26.05 (Yarara)
    CPU: irrelevant
    Memory: irrelevant
    Container: Yes
    Shell: 5.3.9 - /bin/bash
  Binaries:
    Node: 24.13.0 - node
    Yarn: 1.22.22 - yarn
    npm: 11.6.2 - npm
    pnpm: 10.28.0 - pnpm
  npmPackages:
    wxt: ^0.20.6 => 0.20.13

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.

Start by unpacking repro.zip and running npm run zip:firefox, then inspect the zip:firefox entry point and the includeSources handling referenced by wxt.config.ts. Reproduce the archive contents with zipinfo and trace how includeSources and excludeSources are combined. Done means an includeSources-only configuration produces a sources ZIP containing only matching entrypoints while preserving the documented default behavior.