diff --git a/.forgejo/workflows/ci.yml b/.forgejo/workflows/ci.yml
index 184e9b3..5f17846 100644
--- a/.forgejo/workflows/ci.yml
+++ b/.forgejo/workflows/ci.yml
@@ -123,13 +123,18 @@ jobs:
           fi
           # Exclusions mirror --ignore-files in extension/package.json's web-ext
           # scripts: these files are not packaged into the XPI, so touching them
-          # (e.g. Renovate bumping the web-ext devDep) changes nothing shipped
-          # and must not demand a version bump.
+          # (e.g. Renovate bumping the web-ext devDep, or editing a spec)
+          # changes nothing shipped and must not demand a version bump.
+          # KEEP IN SYNC with --ignore-files — a file packaged into the XPI but
+          # excluded here is exactly the silent-stale-ship this job exists to
+          # prevent. test/version.spec.js pins the two lists' shared intent.
           CHANGED=$(git diff --name-only "$BASE" HEAD -- extension/ \
             ':(exclude)extension/package.json' \
             ':(exclude)extension/package-lock.json' \
             ':(exclude)extension/README.md' \
-            ':(exclude)extension/.gitignore')
+            ':(exclude)extension/.gitignore' \
+            ':(exclude)extension/vitest.config.js' \
+            ':(exclude)extension/test/**')
           if [ -z "$CHANGED" ]; then
             echo "No packaged extension files changed since $BASE — nothing to guard."
             echo "OK: extension version $PKG"
diff --git a/.forgejo/workflows/extension.yml b/.forgejo/workflows/extension.yml
index 3a50314..a67c578 100644
--- a/.forgejo/workflows/extension.yml
+++ b/.forgejo/workflows/extension.yml
@@ -1,5 +1,5 @@
 name: extension
-# Lint-only workflow. The sign-and-publish dance moved into build.yml's
+# Lint + unit tests. The sign-and-publish dance moved into build.yml's
 # `sign-extension` job (2026-05-25) — `:latest` now always bundles the XPI
 # because sign-extension runs as a build-web dependency in the SAME workflow,
 # eliminating the prior race between build.yml and a separate extension.yml.
@@ -10,10 +10,15 @@ on:
     paths:
       - 'extension/**'
       - '.forgejo/workflows/extension.yml'
+      # test/version.spec.js asserts ci.yml's extension-version guard never
+      # ignores a file web-ext actually packages, so a ci.yml-only edit can
+      # break this suite and must trigger it.
+      - '.forgejo/workflows/ci.yml'
   pull_request:
     branches: [main]
     paths:
       - 'extension/**'
+      - '.forgejo/workflows/ci.yml'
   workflow_dispatch:
 
 jobs:
@@ -23,7 +28,13 @@ jobs:
       image: node:24-bookworm-slim
     steps:
       - uses: actions/checkout@v4
-      - name: Install web-ext
-        run: cd extension && npm install --no-save --no-audit --no-fund
+      # Not --no-save: vitest and web-ext are both real devDependencies now,
+      # and the suite needs vitest resolvable from node_modules.
+      - name: Install dev dependencies
+        run: cd extension && npm install --no-audit --no-fund
       - name: Lint
         run: cd extension && npm run lint
+      # Pure-logic specs over lib/url.js and lib/platforms.js plus manifest /
+      # package version-consistency checks. No browser, no network.
+      - name: Unit tests
+        run: cd extension && npm run test:unit
diff --git a/ci-requirements.md b/ci-requirements.md
index c5cebd3..c7a5438 100644
--- a/ci-requirements.md
+++ b/ci-requirements.md
@@ -13,10 +13,20 @@ git.fabledsword.com/bvandeusen/ci-python:3.14
 - node (frontend job: `npm install` + vitest + vite build)
 - docker CLI + buildx (`.forgejo/workflows/build.yml`: build-web, build-ml — Fabled-Git registry push)
 
+## Secondary runtime image
+
+node:24-bookworm-slim — `.forgejo/workflows/extension.yml` only.
+
+The extension lane is the one job that does NOT run on `ci-python:3.14`: it
+needs a current Node for `web-ext` and vitest and nothing Python at all. Kept
+on the upstream slim image rather than adding a Node toolchain to `ci-python`,
+per `docs/process.md`'s "add deps to the image when used by >1 project".
+
 ## Per-job tool installs
 
 - `pip install -r requirements.txt pytest pytest-asyncio` — in `backend-lint-and-test` and `integration` jobs
 - `npm install --no-audit --no-fund` — in `frontend-build` job
+- `npm install --no-audit --no-fund` — in `extension.yml`'s `lint` job (web-ext + vitest)
 
 ## Notes
 
@@ -35,3 +45,11 @@ git.fabledsword.com/bvandeusen/ci-python:3.14
   memory bans `npm install` locally). Using `npm install` rather than
   `npm ci` until a lockfile lands.
 - No `imagemagick` / `pandoc` per-job installs needed.
+- `extension/`'s vitest specs load `lib/*.js` by evaluating the real file as a
+  classic script (`test/helpers/loadLib.js`) rather than adding `module.exports`
+  shims to production code — the libs ship as `background.scripts`, not ES
+  modules, so the specs exercise exactly the bytes packaged into the XPI.
+- Extension test files are excluded from the XPI via `--ignore-files` in
+  `extension/package.json`, and the same paths are excluded from `ci.yml`'s
+  `extension-version` guard. Those two lists must agree — `test/version.spec.js`
+  asserts the guard never ignores a file web-ext actually packages.
diff --git a/extension/package.json b/extension/package.json
index 8230440..c441e82 100644
--- a/extension/package.json
+++ b/extension/package.json
@@ -4,12 +4,14 @@
   "private": true,
   "description": "Firefox extension for FabledCurator",
   "scripts": {
-    "lint":  "web-ext lint --source-dir=. --no-config-discovery --ignore-files package.json package-lock.json web-ext-artifacts node_modules README.md .gitignore",
-    "start": "web-ext run --source-dir=. --no-config-discovery --ignore-files package.json package-lock.json web-ext-artifacts node_modules README.md .gitignore --firefox=firefox",
-    "build": "web-ext build --source-dir=. --no-config-discovery --ignore-files package.json package-lock.json web-ext-artifacts node_modules README.md .gitignore --overwrite-dest",
-    "sign":  "web-ext sign --source-dir=. --no-config-discovery --ignore-files package.json package-lock.json web-ext-artifacts node_modules README.md .gitignore --channel=unlisted --api-key=$WEB_EXT_API_KEY --api-secret=$WEB_EXT_API_SECRET"
+    "lint":  "web-ext lint --source-dir=. --no-config-discovery --ignore-files package.json package-lock.json web-ext-artifacts node_modules README.md .gitignore vitest.config.js \"test/**\"",
+    "start": "web-ext run --source-dir=. --no-config-discovery --ignore-files package.json package-lock.json web-ext-artifacts node_modules README.md .gitignore vitest.config.js \"test/**\" --firefox=firefox",
+    "build": "web-ext build --source-dir=. --no-config-discovery --ignore-files package.json package-lock.json web-ext-artifacts node_modules README.md .gitignore vitest.config.js \"test/**\" --overwrite-dest",
+    "sign":  "web-ext sign --source-dir=. --no-config-discovery --ignore-files package.json package-lock.json web-ext-artifacts node_modules README.md .gitignore vitest.config.js \"test/**\" --channel=unlisted --api-key=$WEB_EXT_API_KEY --api-secret=$WEB_EXT_API_SECRET",
+    "test:unit": "vitest run"
   },
   "devDependencies": {
+    "vitest": "^4.0.0",
     "web-ext": "^10.0.0"
   }
 }
diff --git a/extension/test/helpers/loadLib.js b/extension/test/helpers/loadLib.js
new file mode 100644
index 0000000..e5ded02
--- /dev/null
+++ b/extension/test/helpers/loadLib.js
@@ -0,0 +1,29 @@
+import { readFileSync } from 'node:fs'
+import { fileURLToPath } from 'node:url'
+import path from 'node:path'
+
+const LIB_DIR = path.join(path.dirname(fileURLToPath(import.meta.url)), '..', '..', 'lib')
+
+/**
+ * Load an extension lib and hand back the globals it declares.
+ *
+ * The files under lib/ are CLASSIC scripts, not ES modules: manifest.json
+ * lists them in `background.scripts` and options.html pulls them in with a
+ * plain <script> tag, so they declare bare functions into a shared scope and
+ * export nothing. Rather than bolt a `module.exports` shim onto production
+ * code that would never run in the browser, evaluate the real file the same
+ * way the browser does — as a script body — and pick the declarations back out.
+ *
+ * This means the specs exercise the exact bytes that get packaged into the
+ * XPI. Only usable for libs that touch no browser APIs at load time
+ * (url.js, platforms.js); cookies.js and api.js reference `browser.*` and
+ * would need stubbing, which is why they aren't loaded this way.
+ *
+ * @param {string} filename e.g. 'url.js'
+ * @param {string[]} names  declarations to return, e.g. ['normalizeApiUrl']
+ */
+export function loadLib(filename, names) {
+  const source = readFileSync(path.join(LIB_DIR, filename), 'utf8')
+  const factory = new Function(`${source}\nreturn { ${names.join(', ')} }`)
+  return factory()
+}
diff --git a/extension/test/platforms.spec.js b/extension/test/platforms.spec.js
new file mode 100644
index 0000000..deb9f97
--- /dev/null
+++ b/extension/test/platforms.spec.js
@@ -0,0 +1,127 @@
+import { describe, it, expect } from 'vitest'
+import { loadLib } from './helpers/loadLib.js'
+
+const { getPlatformFromUrl, isArtistPage, PLATFORMS, PLATFORM_ARTIST_PATTERNS } = loadLib(
+  'platforms.js',
+  ['getPlatformFromUrl', 'isArtistPage', 'PLATFORMS', 'PLATFORM_ARTIST_PATTERNS']
+)
+
+describe('getPlatformFromUrl', () => {
+  it('identifies each platform from a domain URL', () => {
+    expect(getPlatformFromUrl('https://www.patreon.com/Atole')).toBe('patreon')
+    expect(getPlatformFromUrl('https://subscribestar.adult/someone')).toBe('subscribestar')
+    expect(getPlatformFromUrl('https://www.hentai-foundry.com/user/someone')).toBe('hentaifoundry')
+    expect(getPlatformFromUrl('https://discord.com/channels/@me')).toBe('discord')
+    expect(getPlatformFromUrl('https://www.pixiv.net/en/users/123')).toBe('pixiv')
+    expect(getPlatformFromUrl('https://www.deviantart.com/someone')).toBe('deviantart')
+  })
+
+  it('accepts http as well as https, with or without www', () => {
+    expect(getPlatformFromUrl('http://patreon.com/Atole')).toBe('patreon')
+    expect(getPlatformFromUrl('https://www.patreon.com/Atole')).toBe('patreon')
+  })
+
+  it('returns null for unrelated hosts', () => {
+    expect(getPlatformFromUrl('https://example.com/patreon.com')).toBe(null)
+    expect(getPlatformFromUrl('https://not-patreon.com/Atole')).toBe(null)
+    expect(getPlatformFromUrl('')).toBe(null)
+  })
+})
+
+describe('isArtistPage', () => {
+  // Regression cases from issue #1485: the Add-to-FC button vanished once the
+  // operator SUBSCRIBED to a creator, because Patreon serves subscribed users
+  // the /cw/ ("creator workspace") URL and the pattern only matched the bare
+  // root. All three creator URL shapes must match, plus inner pages — the
+  // button matters most exactly when you're subscribed.
+  it('matches all three Patreon creator URL shapes', () => {
+    expect(isArtistPage('https://www.patreon.com/Atole', 'patreon')).toBe(true)
+    expect(isArtistPage('https://www.patreon.com/c/Atole', 'patreon')).toBe(true)
+    expect(isArtistPage('https://www.patreon.com/cw/Atole', 'patreon')).toBe(true)
+  })
+
+  it('matches Patreon creator inner pages', () => {
+    expect(isArtistPage('https://www.patreon.com/cw/Atole/posts', 'patreon')).toBe(true)
+    expect(isArtistPage('https://www.patreon.com/Atole/membership', 'patreon')).toBe(true)
+  })
+
+  it('excludes Patreon navigation pages that are not creators', () => {
+    for (const nav of ['home', 'search', 'messages', 'notifications', 'library', 'settings']) {
+      expect(isArtistPage(`https://www.patreon.com/${nav}`, 'patreon')).toBe(false)
+      expect(isArtistPage(`https://www.patreon.com/${nav}/anything`, 'patreon')).toBe(false)
+    }
+  })
+
+  it('matches SubscribeStar creator roots on both TLDs but not feed pages', () => {
+    expect(isArtistPage('https://subscribestar.adult/someone', 'subscribestar')).toBe(true)
+    expect(isArtistPage('https://subscribestar.com/someone', 'subscribestar')).toBe(true)
+    expect(isArtistPage('https://subscribestar.adult/feed', 'subscribestar')).toBe(false)
+    expect(isArtistPage('https://subscribestar.adult/messages', 'subscribestar')).toBe(false)
+  })
+
+  it('matches Hentai Foundry user pages only', () => {
+    expect(isArtistPage('https://www.hentai-foundry.com/user/someone', 'hentaifoundry')).toBe(true)
+    expect(isArtistPage('https://www.hentai-foundry.com/pictures/popular', 'hentaifoundry')).toBe(
+      false
+    )
+  })
+
+  it('matches Pixiv numeric user pages, with or without the /en/ prefix', () => {
+    expect(isArtistPage('https://www.pixiv.net/users/12345', 'pixiv')).toBe(true)
+    expect(isArtistPage('https://www.pixiv.net/en/users/12345', 'pixiv')).toBe(true)
+    expect(isArtistPage('https://www.pixiv.net/en/artworks/999', 'pixiv')).toBe(false)
+  })
+
+  it('excludes DeviantArt navigation roots', () => {
+    expect(isArtistPage('https://www.deviantart.com/someone', 'deviantart')).toBe(true)
+    expect(isArtistPage('https://www.deviantart.com/home', 'deviantart')).toBe(false)
+    expect(isArtistPage('https://www.deviantart.com/watch', 'deviantart')).toBe(false)
+  })
+
+  it('returns false for a platform with no artist pattern (discord)', () => {
+    expect(isArtistPage('https://discord.com/channels/@me', 'discord')).toBe(false)
+  })
+
+  it('returns false for an unknown platform key', () => {
+    expect(isArtistPage('https://www.patreon.com/Atole', 'nope')).toBe(false)
+  })
+})
+
+describe('platform table integrity', () => {
+  it('gives every artist pattern a corresponding platform entry', () => {
+    // A pattern keyed to a platform that no longer exists is dead code that
+    // silently never fires; the reverse (a platform with no pattern) is the
+    // legitimate discord case, so only this direction is an error.
+    for (const key of Object.keys(PLATFORM_ARTIST_PATTERNS)) {
+      expect(Object.keys(PLATFORMS)).toContain(key)
+    }
+  })
+
+  it('gives every platform the fields the popup renders', () => {
+    for (const [key, platform] of Object.entries(PLATFORMS)) {
+      expect(platform.name, `${key}.name`).toBeTruthy()
+      expect(platform.color, `${key}.color`).toMatch(/^#[0-9A-Fa-f]{6}$/)
+      expect(['cookies', 'token'], `${key}.authType`).toContain(platform.authType)
+      expect(platform.urlPattern, `${key}.urlPattern`).toBeInstanceOf(RegExp)
+      expect(Array.isArray(platform.domains), `${key}.domains`).toBe(true)
+      expect(platform.domains.length, `${key}.domains`).toBeGreaterThan(0)
+    }
+  })
+
+  it('keeps every artist URL matched by its own platform pattern too', () => {
+    // isArtistPage is only ever consulted after getPlatformFromUrl resolves a
+    // key, so an artist pattern matching a URL its platform's urlPattern
+    // rejects would be unreachable.
+    const samples = {
+      patreon: 'https://www.patreon.com/cw/Atole',
+      subscribestar: 'https://subscribestar.adult/someone',
+      hentaifoundry: 'https://www.hentai-foundry.com/user/someone',
+      deviantart: 'https://www.deviantart.com/someone',
+      pixiv: 'https://www.pixiv.net/en/users/12345'
+    }
+    for (const [key, url] of Object.entries(samples)) {
+      expect(isArtistPage(url, key), `${key} artist pattern`).toBe(true)
+      expect(getPlatformFromUrl(url), `${key} urlPattern`).toBe(key)
+    }
+  })
+})
diff --git a/extension/test/url.spec.js b/extension/test/url.spec.js
new file mode 100644
index 0000000..a5fca10
--- /dev/null
+++ b/extension/test/url.spec.js
@@ -0,0 +1,93 @@
+import { describe, it, expect } from 'vitest'
+import { loadLib } from './helpers/loadLib.js'
+
+const { normalizeApiUrl, webRootFromApiUrl } = loadLib('url.js', [
+  'normalizeApiUrl',
+  'webRootFromApiUrl'
+])
+
+describe('normalizeApiUrl', () => {
+  // The bug this exists for (issue #2393): the instance root was accepted and
+  // stored verbatim, so every request went to /credentials instead of
+  // /api/credentials. That path is a Vue router route, so the SPA catch-all
+  // answered GET with 200 HTML and rejected POST with 405 — which read as a
+  // backend bug rather than a URL one.
+  it('appends /api to an instance root', () => {
+    expect(normalizeApiUrl('http://curator.traefik.internal')).toBe(
+      'http://curator.traefik.internal/api'
+    )
+  })
+
+  it('leaves an API root alone rather than doubling the suffix', () => {
+    expect(normalizeApiUrl('http://curator.traefik.internal/api')).toBe(
+      'http://curator.traefik.internal/api'
+    )
+  })
+
+  it('is idempotent', () => {
+    const once = normalizeApiUrl('http://curator.example.com')
+    expect(normalizeApiUrl(once)).toBe(once)
+  })
+
+  it('strips trailing slashes before deciding', () => {
+    expect(normalizeApiUrl('http://curator.example.com/')).toBe('http://curator.example.com/api')
+    expect(normalizeApiUrl('http://curator.example.com///')).toBe('http://curator.example.com/api')
+    expect(normalizeApiUrl('http://curator.example.com/api/')).toBe('http://curator.example.com/api')
+  })
+
+  it('trims surrounding whitespace (paste artifacts)', () => {
+    expect(normalizeApiUrl('  http://curator.example.com  ')).toBe(
+      'http://curator.example.com/api'
+    )
+  })
+
+  it('matches the /api suffix case-insensitively', () => {
+    expect(normalizeApiUrl('http://curator.example.com/API')).toBe('http://curator.example.com/API')
+  })
+
+  it('returns empty string for empty/nullish input, never a bare "/api"', () => {
+    // isConfigured() gates on truthiness, so a bogus '/api' here would read as
+    // "configured" and produce a request against the options page's own origin.
+    expect(normalizeApiUrl('')).toBe('')
+    expect(normalizeApiUrl('   ')).toBe('')
+    expect(normalizeApiUrl(null)).toBe('')
+    expect(normalizeApiUrl(undefined)).toBe('')
+  })
+
+  it('does not treat a path merely containing "api" as the suffix', () => {
+    expect(normalizeApiUrl('http://curator.example.com/apiary')).toBe(
+      'http://curator.example.com/apiary/api'
+    )
+  })
+
+  it('preserves a subpath deployment', () => {
+    expect(normalizeApiUrl('http://host.internal/curator')).toBe('http://host.internal/curator/api')
+  })
+})
+
+describe('webRootFromApiUrl', () => {
+  // The SPA root, where the Vue router and the served XPI live. Used by
+  // OPEN_ARTIST_PAGE and the self-update check — NOT the JSON API.
+  it('strips the /api suffix', () => {
+    expect(webRootFromApiUrl('http://curator.example.com/api')).toBe('http://curator.example.com')
+  })
+
+  it('accepts an instance root unchanged', () => {
+    expect(webRootFromApiUrl('http://curator.example.com')).toBe('http://curator.example.com')
+  })
+
+  it('agrees with normalizeApiUrl in both directions', () => {
+    for (const input of ['http://curator.example.com', 'http://curator.example.com/api']) {
+      expect(normalizeApiUrl(webRootFromApiUrl(input))).toBe(normalizeApiUrl(input))
+    }
+  })
+
+  it('preserves a subpath deployment', () => {
+    expect(webRootFromApiUrl('http://host.internal/curator/api')).toBe('http://host.internal/curator')
+  })
+
+  it('returns empty string for empty/nullish input', () => {
+    expect(webRootFromApiUrl('')).toBe('')
+    expect(webRootFromApiUrl(null)).toBe('')
+  })
+})
diff --git a/extension/test/version.spec.js b/extension/test/version.spec.js
new file mode 100644
index 0000000..f5cdf59
--- /dev/null
+++ b/extension/test/version.spec.js
@@ -0,0 +1,71 @@
+import { describe, it, expect } from 'vitest'
+import { readFileSync } from 'node:fs'
+import { fileURLToPath } from 'node:url'
+import path from 'node:path'
+
+const EXT_DIR = path.join(path.dirname(fileURLToPath(import.meta.url)), '..')
+const read = (name) => JSON.parse(readFileSync(path.join(EXT_DIR, name), 'utf8'))
+
+describe('extension version consistency', () => {
+  // Duplicates check (1) of ci.yml's extension-version job, deliberately.
+  // That job is the gate that can't be bypassed; this spec is the one that
+  // fails in a second on the developer's own CI lane with a readable diff.
+  // The two version strings feed different systems and nothing else reconciles
+  // them:
+  //   manifest.json  -> what `web-ext sign` signs, so what Firefox installs
+  //                     (package.json is in --ignore-files, not in the XPI)
+  //   package.json   -> build.yml's AMO cache key, the ext-<version> release
+  //                     tag, the XPI filename, and therefore the version
+  //                     /api/extension/manifest reports to the update prompt
+  it('keeps manifest.json and package.json in lockstep', () => {
+    const manifest = read('manifest.json')
+    const pkg = read('package.json')
+    expect(manifest.version).toBe(pkg.version)
+  })
+
+  it('uses a plain dotted numeric version AMO will accept', () => {
+    // AMO rejects exotic version strings, and build.yml embeds this value in a
+    // release tag and a filename — so anything needing escaping breaks the
+    // publish path rather than the extension.
+    expect(read('package.json').version).toMatch(/^\d+(\.\d+)*$/)
+  })
+
+  it('declares manifest v3', () => {
+    expect(read('manifest.json').manifest_version).toBe(3)
+  })
+
+  it('never lets the CI guard ignore a file that actually ships', () => {
+    // ci.yml's extension-version job skips its bump check for paths it deems
+    // non-shipping. If it excludes something web-ext DOES package, a real
+    // change to shipped code passes the guard unnoticed — precisely the
+    // silent-stale-ship the guard exists to stop. The reverse drift (guard
+    // stricter than web-ext) only costs a needless bump, so it isn't asserted.
+    const ci = readFileSync(path.join(EXT_DIR, '..', '.forgejo', 'workflows', 'ci.yml'), 'utf8')
+    const lint = read('package.json').scripts.lint
+    const after = lint.split('--ignore-files')[1] ?? ''
+    const ignored = new Set(
+      after
+        .split(/\s+/)
+        .filter((tok) => tok && !tok.startsWith('--'))
+        .map((tok) => tok.replace(/^["']|["']$/g, ''))
+    )
+    expect(ignored.size, 'parsed --ignore-files from the lint script').toBeGreaterThan(0)
+
+    const guarded = [...ci.matchAll(/:\(exclude\)extension\/(\S+?)'/g)].map((m) => m[1])
+    expect(guarded.length, 'parsed :(exclude) entries from ci.yml').toBeGreaterThan(0)
+    for (const entry of guarded) {
+      expect(ignored, `ci.yml excludes "${entry}" but web-ext packages it`).toContain(entry)
+    }
+  })
+
+  it('lists every background script that exists, in dependency order', () => {
+    // url.js must load BEFORE api.js: api.js calls normalizeApiUrl at
+    // init()-time, and these are classic scripts sharing one scope, so a
+    // reordering here is a runtime ReferenceError with no build-time signal.
+    const scripts = read('manifest.json').background.scripts
+    for (const rel of scripts) {
+      expect(() => readFileSync(path.join(EXT_DIR, rel)), `missing ${rel}`).not.toThrow()
+    }
+    expect(scripts.indexOf('lib/url.js')).toBeLessThan(scripts.indexOf('lib/api.js'))
+  })
+})
diff --git a/extension/vitest.config.js b/extension/vitest.config.js
new file mode 100644
index 0000000..a6f405f
--- /dev/null
+++ b/extension/vitest.config.js
@@ -0,0 +1,13 @@
+import { defineConfig } from 'vitest/config'
+
+// Mirrors frontend/vitest.config.js, minus the Vue plugin — the extension has
+// no SFCs and mounts nothing. Pure-logic specs only, so `node` is enough; the
+// libs under test are deliberately the ones with no browser-API surface (see
+// test/helpers/loadLib.js).
+export default defineConfig({
+  test: {
+    environment: 'node',
+    include: ['test/**/*.spec.js'],
+    passWithNoTests: true
+  }
+})