i18n: full pass + culture-aware dates/sizes + Software Update License wording

- Strings.cs : ~80 new keys covering status messages, progress detail
  (DL/extraction/verify), license summary, license details dialog, onboarding
  statuses, settings field labels, restart/cancel/quit confirmations, toasts,
  resume choice, copyright. Strings.FormatSize and Strings.FormatDate /
  FormatLongDate switch units (o/Ko vs B/KB) and pattern (dd/MM/yyyy vs M/d/yyyy
  vs 2026年) by active language.
- License terminology renamed across UI: "License" → "License de mise à jour"
  / "Software Update License" to clarify it gates UPDATES, not Proserve itself.
  Expired/revoked dialogs now spell out "you can still download versions
  released before this date and launch any installed version".
- "🔒 License insuffisante" → "🔒 License de mise à jour requise pour cette
  version" / "Valid update license needed for this version" so users understand
  it's a per-version eligibility check, not a global block.
- All hardcoded FR strings in views (SettingsDialog labels, LicenseDetails
  fields, Onboarding statuses, dialog titles, copyright, window chrome
  tooltips, "Sortie le", etc.) replaced with x:Static loc bindings.
- All FormatSize duplicates (5 places) and date format strings (8 places)
  delegate to Strings helpers — single source of truth for localization.
- Settings dialog: License section moved to the top before Language. It's
  the most important info and conditions what the user can download.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

src/PSLauncher.App/Views/LicenseDetailsDialog.xaml.cs

@@ -29,11 +29,11 @@ public partial class LicenseDetailsDialog : Window
 
         OwnerText.Text = license.OwnerName ?? "—";
         UntilText.Text = license.DownloadEntitlementUntil is { } until
-            ? $"jusqu'au {until.ToLocalTime():dddd dd MMMM yyyy}"
+            ? Strings.FormatLongDate(until)
             : "—";
         IssuedText.Text = license.IssuedAt is { } issued
-            ? issued.ToLocalTime().ToString("dd/MM/yyyy")
-            : (license.ServerTime?.ToLocalTime().ToString("dd/MM/yyyy") ?? "—");
+            ? Strings.FormatDate(issued)
+            : Strings.FormatDate(license.ServerTime);
         MachineIdText.Text = licenseService.GetMachineId();
     }
 
@@ -43,19 +43,19 @@ public partial class LicenseDetailsDialog : Window
         if (l.Status == "valid")
         {
             if (until is { } u && (u - DateTime.UtcNow).TotalDays < 30)
-                return ("⏰", "License valide", $"Expire bientôt — le {u.ToLocalTime():dd/MM/yyyy}",
+                return ("⏰", Strings.LicenseDetailsValidTitle, Strings.LicenseDetailsExpiringSoon(Strings.FormatDate(u)),
                     Color.FromRgb(0xF5, 0x9E, 0x0B), Color.FromRgb(0x3A, 0x2A, 0x0E));
-            return ("✓", "License valide", "Téléchargements de nouvelles versions autorisés",
+            return ("✓", Strings.LicenseDetailsValidTitle, Strings.LicenseDetailsValidSubtitle,
                 Color.FromRgb(0x16, 0xA3, 0x4A), Color.FromRgb(0x0E, 0x2A, 0x1B));
         }
         if (l.Status == "expired")
-            return ("⚠", "License expirée",
-                until is { } u ? $"Expirée le {u.ToLocalTime():dd/MM/yyyy}" : "Plus de téléchargements possibles",
+            return ("⚠", Strings.LicenseDetailsExpiredTitle,
+                until is { } u ? Strings.LicenseDetailsExpiredSubtitle(Strings.FormatDate(u)) : Strings.LicenseDetailsExpiredFallback,
                 Color.FromRgb(0xEF, 0x44, 0x44), Color.FromRgb(0x2A, 0x14, 0x14));
         if (l.Status == "revoked")
-            return ("🚫", "License révoquée", "Contacte ASTERION pour plus d'informations",
+            return ("🚫", Strings.LicenseDetailsRevokedTitle, Strings.LicenseDetailsRevokedSubtitle,
                 Color.FromRgb(0xEF, 0x44, 0x44), Color.FromRgb(0x2A, 0x14, 0x14));
-        return ("❓", "License inconnue", l.Message ?? l.Status,
+        return ("❓", Strings.LicenseDetailsUnknownTitle, l.Message ?? l.Status,
             Color.FromRgb(0xEF, 0x44, 0x44), Color.FromRgb(0x2A, 0x14, 0x14));
     }