feat(l10n): replace legacy %@ format keys with semantic template keys

The Apple catalog carried four stringly-named passthrough keys ("%@",
"%@ · %@", "%@ %@ · %@", "%@%%") left over from the KMP port. They were
never referenced as keys — the composite strings were built inline with
hardcoded separators, so the middot/percent formatting wasn't localizable.

Renames them to proper semantic keys in strings.json:
  - format_separated_pair(first:second:)     "{first} · {second}"
  - format_separated_triple(first:second:third:)
  - battery_level_value(level:)              "{level}%"
and drops the pure-identity "%@". Wires the inline compositions (size ·
status, count files · size, receivers pending · completed, battery level)
to the generated typed accessors. Catalog now validates with zero warnings.

apple/VniDrop/Platform/AppDependencies+iOS.swift

@@ -36,7 +36,7 @@ private struct IosDeviceInfoProvider: DeviceInfoProvider {
 			device.isBatteryMonitoringEnabled = true
 			defer { device.isBatteryMonitoringEnabled = wasMonitoring }
 			let level = device.batteryLevel
-			return level >= 0 ? "\(Int(level * 100))%" : nil
+			return level >= 0 ? L10n.Battery.levelValue(level: "\(Int(level * 100))") : nil
 		}()
 		return DeviceInfo(
 			deviceName: device.name,