Update interface translations

Changes add and edit English only; this update translates them into every other interface language. Run everything from apps/web. Conventions are in .agents/rules/web/i18n.md; wording is in src/lib/i18n/glossary.md.

1. Start from main

git fetch origin main && git checkout -B i18n/update-<yyyy-mm-dd> origin/main.

2. Find untranslated text

• bun run i18n:status --json lists, per language, messages that are missing (no translation), stale (the English changed since it was translated), or have a placeholderMismatch.
• English that never went through t() doesn't show there. Literal labels on menu items fail CI (tsx-menu-label-translated), but other surfaces can slip through: labels in config objects (label: 'Foo'), sidebar and command definitions, tab names. Read the apps/web/src diff of changes merged since the last update (git log --since='8 days ago' --format='%h %s' origin/main -- apps/web/src) for user-visible text with a string literal in new UI, menus, or navigation. Move each into src/lib/i18n/locales/en/<namespace>.ts and render it with t(), following the rule. Leave surfaces that aren't translated yet (most page content; the slides, canvas, spreadsheet, and database editors) alone, so no page mixes languages.

Nothing missing, stale, or newly converted: stop, without a branch or PR.

3. Translate

For each key, write the translation in every src/lib/i18n/locales/<language>.ts file, in the key's namespace, in the same order as English.

• Translate from the current English and the surface it appears on (find it with grep -rn "'<namespace>.<key>'" src), not from the old translation.
• Use the glossary's form of address and its words for product terms. A new product term gets a row in every language's glossary table.
• Keep {{placeholders}} exactly; use the language's quotation marks.
• A plural English message (an object such as { one, other }) is an object in every language, with exactly the language's plural categories: new Intl.PluralRules('<language>').resolvedOptions().pluralCategories (Polish and Russian one, few, many, other; French, Spanish, Italian and Portuguese add many for millions; Japanese, Korean, Chinese, Indonesian, Vietnamese and Thai only other). The tests check the forms.
• Prefer the shorter of two equally clear wordings; menus cap at 22rem.
• Don't touch translations that aren't missing or stale, and never edit the English.

4. Record and check

1. bun run i18n:status --accept all, then bun run i18n:status: every language reports up to date.
2. bun run test -- src/lib/i18n passes (stray keys, placeholders).
3. just test-i18n-browser passes in every language. A clipped label lists its text: shorten that translation rather than widening the menu. The check renders every key in the context-menu namespaces; a label in another namespace that renders in a narrow space gets added to MENUS in src/lib/i18n/browser-test/menus.tsx.
4. Converted any literals in step 2? bunx --yes @ast-grep/cli@0.44.1 scan from the repository root, and the tests of the touched features.

5. Open the PR

Commit and open a ready-for-review PR per the git skill, titled like chore(web): update interface translations. Say which messages changed and why (new, changed English, converted literals), and list any glossary terms added so a native speaker can check them.