feat(apple): generate type-safe L10n accessors and migrate all key literals

Replaces every stringly-typed localization key in the Apple app with
compile-time-checked accessors generated from localization/strings.json.
A mistyped key is now a build error instead of a silent fallback to the
raw key at runtime. The runtime path is unchanged: plain keys are
String.LocalizationValue constants resolved with String(localized:) and
Apple's String Catalog still does the lookup; keys with arguments become
typed, named functions applying args through String(format:).

Generator: new renderSwiftAccessors emits apple/VniDrop/Generated/L10n.swift,
wired into generate. Renamed generic arg1/arg2 tokens on four keys to
semantic names (receiver, transferName, deviceId) and updated their context
notes; positional output is unchanged so .xcstrings (bar the 4 comments)
and the Android XML regenerate identical.

Migration: every key-carrying value flipped to String.LocalizationValue
end to end, resolved only at the leaf. Zero key literals and zero
LocalizedStringKey remain in app or test code. macOS build passes; iOS
test run pending.

localization/src/config.ts

@@ -18,6 +18,12 @@ export const APPLE_INFO_PLIST = join(
   "apple/VniDrop/Resources/Info.plist",
 );
 
+/** Generated Swift accessors (`L10n`) for compile-time-checked catalog keys. */
+export const APPLE_L10N_SWIFT = join(
+  REPO_ROOT,
+  "apple/VniDrop/Generated/L10n.swift",
+);
+
 /** KMP / Compose Multiplatform resources root; one values[-lang]/strings.xml per language. */
 export const KMP_RESOURCES = join(
   REPO_ROOT,