Rename the darker tone to AMOLED; file icons are always colored

- Tone: the "darker" option is labelled "AMOLED" in all 7 locales — it is
  the true-black AMOLED palette. The persisted value stays "darker", so no
  settings migration.
- File icons: the Plain/Multi option is gone and the per-category glyphs +
  colors are always on. Removed the iconColors setting (type, default,
  signal, setter, options row, strings) and the plain branch in
  file-icons.ts. A stale "iconColors" key in settings.json is carried
  harmlessly and dropped on the next save.

Co-Authored-By: Claude <noreply@anthropic.com>

src/shared/i18n/fr.ts

@@ -34,7 +34,7 @@ export const fr = {
 		language: "Langue",
 		system: "Système",
 		theme: { label: "Thème", system: "Système", light: "Clair", dark: "Sombre" },
-		tone: { label: "Ton", dark: "Sombre", darker: "Plus sombre" },
+		tone: { label: "Ton", dark: "Sombre", darker: "AMOLED" },
 		accent: { label: "Accent" },
 		accentNames: {
 			graphite: "Graphite",
@@ -46,7 +46,6 @@ export const fr = {
 			green: "Vert",
 			teal: "Sarcelle",
 		},
-		fileIcons: { label: "Icônes", plain: "Simple", multi: "Couleur" },
 		interface: { label: "Interface", smaller: "Plus petite", larger: "Plus grande", reset: "Réinitialiser à 100%" },
 		speedUnit: { label: "Unité de vitesse" },
 		transfers: { label: "Transferts", single: "Un", multi: "Plusieurs" },