QA: First-time language setup

Accepted together with features/language_setup.feature.

Automated, no server (task test)

Use case over in-memory fakes: "Apply for every pending site", "The owner may change a suggestion", "Retrying is safe", "A site with no articles still needs confirming", refused rows. Assert sentinels with errors.Is. Assert that the whole apply is one Transactor call and that site-row locks are taken in ascending site id order.
HTTP: NewHandler over the use case, a fresh chi.NewRouter mirroring api/router.go under /v1/language, behind require(role.KeySettingsManageSites), validator.InitValidator(), httptest. Cover 200, 400, 401, 403, 404, 409 and 422 with exact plain-text bodies and the JSON key set. setup_in_progress is simulated by a fake whose apply returns the sentinel.
Regression: slice 1 tests ("Create racing a confirmation", "Assigning a language is idempotent") untouched.

Fixture: the four sites above with 8, 3, 5 and 0 articles, one soft-deleted. POST applies; assert ids, titles, bodies, slugs, is_online, story ids and timestamps unchanged; soft-deleted articles are assigned too; no pending site remains; a second POST changes nothing (hash of all rows). A site created after migration with no row is listed and can be confirmed.
Atomicity: inject a failing write on the second site; assert no row is confirmed and no article is assigned; the next POST completes.
Concurrency: goroutines creating articles during setup; every final lang equals the confirmed tag; bound the SQLITE_BUSY retries. Two concurrent POSTs: one 200, the other 200 or 409 setup_in_progress, never a deadlock.

One targeted run of steps 4 to 6 on MySQL 8.4, MariaDB 11 and PostgreSQL, sharing the run planned in the site_languages QA. Check lock ordering for deadlocks. Record NOT RUN if the daemon is down, or use the podman shim.

One spec per row of "Setup states". Assert the copy, the disabled confirm button until every row has a language, that Journal and Archive are seeded and Notes is not, the single POST body, and the 409 / 500 transitions.
Mock set: GET with Journal, Notes, Archive (8, 3, 5 articles); GET with only Notes; GET with only Gallery; GET with nothing pending; GET with a substituted suggestion; POST 200 { assigned: 16 }; POST 409; POST 500.
Route guard: a reader is redirected; an owner reaches the page; the back link goes to /settings/sites/:key/languages, and to Settings, Sites for an unknown :key.
The Languages page banner links to /settings/sites/:key/languages/setup when needs_setup is true.
task test:web, the type check, bun lint, and a diff check for comments.

Run once at the end of the slice (group L2, 7 states) with the board fixtures Journal, Notes, Archive and Gallery (SETUP in locale-fixtures.js: 8, 3 and 5 articles). Desktop 1440 and mobile 390, light and dark.
Not checked visually (no frame): nothing-pending, unknown :key, substituted seed.

Nothing pending: the Done alert without a count.
Substituted seed: the Languages "broader" wording.
Unknown or complete 🔑 the global list is shown and the back link falls back to Settings, Sites.
Setup route: one global page (Option 1), reached from a per-site banner.

Skipped list and stable lock loop: TestLanguageSetupSkippedChoices, TestLanguageSetupLocksUntilStable (test/localization_fix_http_test.go).
Setup activity events: TestLanguageActivity.
Two simultaneous setups on SQLite: TestLanguageConcurrencyOnSQLite.

Keyboard order and focus return after "Try again" and "Check again".
Real two-owner run: start setup in two browsers and confirm the second sees "Setup is already running".
A copy of a real database with articles: run setup, check the articles list and one public read still match, then restart and confirm nothing changes.