localization: ship fr-FR

Complete French catalog across all three namespaces (app/panel/ui),
1129 keys, machine-translated then reviewed for the two things that
go wrong automatically: technical vocabulary and plurals.

Fixed on review: a gender-agreement slip ("décrivez-la" referring to
the masculine "Prompt", should be "décrivez-le") and an incomplete
verb construction in agentRunner.keepsGoing. Also reverted "Minesweeper"
→ "Démineur" back to the untranslated proper name, matching pt-PT's
own precedent of not translating this bundled app's name.

French is the language where the 0/1/2 plural check actually bites:
Intl.PluralRules puts count=0 in the SAME category as count=1 ("one"),
unlike English/Portuguese/German/Spanish where 0 is "other". All 17
plural entries were verified against 0, 1 and 2 rather than trusting
the category names — the "one" branch is phrased as a plain singular
so it reads correctly for both 0 and 1.

Parity tests now check every non-en locale in one assertion instead
of hardcoding pt-PT; SHIPPED_LOCALES gains fr-FR so the picker offers
it. es-ES and de-DE catalogs are drafted and under review — held out
of this commit and out of SHIPPED_LOCALES until each passes its own
review, so a half-translated locale never reaches the picker.

src/workspaces/components/locales/parity.test.ts

@@ -2,11 +2,12 @@ import { describe, expect, test } from 'bun:test';
 import { findMissingKeys } from 'i18n';
 import en from './en-GB.json';
 import ptPT from './pt-PT.json';
+import frFR from './fr-FR.json';
 
-// D2: every shipped locale ships a COMPLETE catalog. Phase 0 scaffolds this catalog with no keys yet
-// (ui.* strings land in phase 1) — the test still runs so it is load-bearing from day one.
+// D2: every shipped locale ships a COMPLETE catalog. A key en-GB has and another locale lacks is a red
+// build, not a warning — there is no regional fallback to paper over the gap.
 describe('shared components (ui.*) locale catalogs', () => {
-  test('pt-PT has every key en-GB has', () => {
-    expect(findMissingKeys(en, { 'pt-PT': ptPT })).toEqual([]);
+  test('every shipped locale has every key en-GB has', () => {
+    expect(findMissingKeys(en, { 'pt-PT': ptPT, 'fr-FR': frFR })).toEqual([]);
   });
 });