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/commands/generate.ts

@@ -5,8 +5,11 @@
  */
 import { mkdirSync } from "node:fs";
 import { join } from "node:path";
+import { mkdir } from "node:fs/promises";
+import { dirname } from "node:path";
 import {
   APPLE_INFO_PLIST,
+  APPLE_L10N_SWIFT,
   APPLE_XCSTRINGS,
   kmpValuesDir,
   KMP_RESOURCES,
@@ -14,6 +17,7 @@ import {
 } from "../config";
 import { renderAndroid, type ParsedAndroid } from "../lib/android-xml";
 import { fromCanonical, type Flavor } from "../lib/placeholders";
+import { renderSwiftAccessors } from "../lib/swift-accessors";
 import { renderXcstrings, type XcCatalog, type XcEntry } from "../lib/xcstrings";
 import { targetsOf, type StringEntry, type StringsFile } from "../types";
 
@@ -111,6 +115,10 @@ export async function generate() {
   await Bun.write(APPLE_XCSTRINGS, renderXcstrings(buildXcstrings(doc)));
   console.log(`Wrote ${APPLE_XCSTRINGS}`);
 
+  await mkdir(dirname(APPLE_L10N_SWIFT), { recursive: true });
+  await Bun.write(APPLE_L10N_SWIFT, renderSwiftAccessors(doc));
+  console.log(`Wrote ${APPLE_L10N_SWIFT}`);
+
   await syncInfoPlistLocalizations(doc.supportedLanguages);
 
   for (const lang of doc.supportedLanguages) {

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,

localization/src/lib/swift-accessors.ts

@@ -0,0 +1,139 @@
+/**
+ * Swift accessor generator.
+ *
+ * Emits a compile-time-checked stand-in for each localization key so Apple call
+ * sites stop passing raw string literals. The runtime path is unchanged: plain
+ * keys become `String.LocalizationValue` constants used with `String(localized:)`
+ * exactly as before, and Apple's catalog lookup still does 100% of the work.
+ *
+ * Keys group by their first `_`-delimited segment (`button_…` -> `enum Button`);
+ * the remainder becomes a camelCase member. Plain keys are `static let`
+ * constants; keys with args become `static func` with typed, named parameters
+ * derived from the entry's `args` metadata.
+ */
+import { targetsOf, type Arg, type StringEntry, type StringsFile } from "../types";
+
+const HEADER = `// Generated by localization/ (bun run src/cli.ts generate). Do not edit.
+// Keys resolve through Apple's String Catalog exactly as a literal would; these
+// accessors only make the key compile-time-checked. If a runtime language
+// switcher (live \`.environment(\\.locale)\`) is ever added, switch the plain
+// \`static let\` constants to computed \`static var\` so the locale is not frozen.
+import Foundation
+`;
+
+/** Swift type for a localization arg. */
+function swiftType(arg: Arg): string {
+  switch (arg.type) {
+    case "int":
+      return "Int";
+    case "double":
+      return "Double";
+    case "string":
+      return "String";
+  }
+}
+
+/** `create_new_transfer` -> `createNewTransfer`. */
+function camel(segment: string): string {
+  const parts = segment.split("_").filter(Boolean);
+  return parts
+    .map((p, i) => (i === 0 ? p : p.charAt(0).toUpperCase() + p.slice(1)))
+    .join("");
+}
+
+/** `button` -> `Button`. */
+function pascal(segment: string): string {
+  const c = camel(segment);
+  return c.charAt(0).toUpperCase() + c.slice(1);
+}
+
+/** A key is groupable only when it starts with an identifier-safe segment. */
+function isGroupableKey(key: string): boolean {
+  return /^[A-Za-z][A-Za-z0-9_]*$/.test(key);
+}
+
+/** Collapse whitespace/newlines so a value fits on one doc-comment line. */
+function oneLine(text: string): string {
+  return text.replace(/\s*\n\s*/g, " ").trim();
+}
+
+/** The displayable text for a language (plural shows its `other` form). */
+function translationText(entry: StringEntry, lang: string): string | undefined {
+  return entry.translations?.[lang] ?? entry.plural?.[lang]?.other;
+}
+
+/**
+ * A rich Quick Help block: source-language text as the abstract, then the raw
+ * key, the context note, and every translation. Quick Help renders the Markdown.
+ */
+function docComment(key: string, entry: StringEntry, doc: StringsFile): string {
+  const lines: string[] = [];
+  const source = translationText(entry, doc.sourceLanguage);
+  if (source) lines.push(oneLine(source), "");
+
+  lines.push(`Key: \`${key}\``);
+  if (entry.context) lines.push(`Context: ${oneLine(entry.context)}`);
+  lines.push("");
+
+  for (const lang of doc.supportedLanguages) {
+    const value = translationText(entry, lang);
+    if (value !== undefined) lines.push(`- ${lang}: ${oneLine(value)}`);
+  }
+
+  return lines
+    .map((line) => (line ? `        /// ${line}` : "        ///"))
+    .join("\n");
+}
+
+function memberFor(
+  key: string,
+  member: string,
+  entry: StringEntry,
+  doc: StringsFile,
+): string {
+  const comment = docComment(key, entry, doc);
+  const args = entry.args ?? [];
+
+  // Plain key: a #define-style constant. Apple resolves it via String(localized:).
+  if (args.length === 0 && !entry.plural) {
+    return `${comment}\n        static let ${member}: String.LocalizationValue = "${key}"`;
+  }
+
+  // Arg'd (or plural) key: a typed, named function that applies the arguments
+  // through the same String(format: String(localized:)) path used before.
+  const params = args.map((a) => `${a.name}: ${swiftType(a)}`).join(", ");
+  const callArgs = args.map((a) => a.name).join(", ");
+  // The positional format string lives in the catalog; look it up by key and
+  // apply the args exactly as the hand-written call sites did.
+  return `${comment}\n        static func ${member}(${params}) -> String {\n            String(format: String(localized: "${key}"), ${callArgs})\n        }`;
+}
+
+export function renderSwiftAccessors(doc: StringsFile): string {
+  // group segment -> rendered members
+  const groups = new Map<string, string[]>();
+
+  for (const [key, entry] of Object.entries(doc.strings)) {
+    if (!targetsOf(entry).includes("apple")) continue;
+    if (!isGroupableKey(key)) continue; // skips legacy `%@` literal keys
+
+    const underscore = key.indexOf("_");
+    const groupSeg = underscore === -1 ? key : key.slice(0, underscore);
+    const memberSeg = underscore === -1 ? key : key.slice(underscore + 1);
+    const group = pascal(groupSeg);
+    const member = camel(memberSeg) || camel(groupSeg);
+
+    const list = groups.get(group) ?? [];
+    list.push(memberFor(key, member, entry, doc));
+    groups.set(group, list);
+  }
+
+  const body = [...groups.keys()]
+    .sort()
+    .map((group) => {
+      const members = groups.get(group)!.join("\n");
+      return `    enum ${group} {\n${members}\n    }`;
+    })
+    .join("\n");
+
+  return `${HEADER}\nenum L10n {\n${body}\n}\n`;
+}

localization/strings.json

@@ -476,23 +476,23 @@
       }
     },
     "approval_endpoint_id": {
-      "context": "Approval prompt: shows the requesting device's ID. {arg1} = device/endpoint identifier.",
+      "context": "Approval prompt: shows the requesting device's ID. {deviceId} = device/endpoint identifier.",
       "args": [
         {
-          "name": "arg1",
+          "name": "deviceId",
           "type": "string"
         }
       ],
       "translations": {
-        "en": "Device ID: {arg1}",
-        "fr": "Identifiant de l’appareil : {arg1}",
-        "es": "ID del dispositivo: {arg1}",
-        "it": "ID dispositivo: {arg1}",
-        "de": "Geräte-ID: {arg1}",
-        "pt": "ID do dispositivo: {arg1}",
-        "pl": "Identyfikator urządzenia: {arg1}",
-        "nl": "Apparaat-ID: {arg1}",
-        "ru": "Идентификатор устройства: {arg1}"
+        "en": "Device ID: {deviceId}",
+        "fr": "Identifiant de l’appareil : {deviceId}",
+        "es": "ID del dispositivo: {deviceId}",
+        "it": "ID dispositivo: {deviceId}",
+        "de": "Geräte-ID: {deviceId}",
+        "pt": "ID do dispositivo: {deviceId}",
+        "pl": "Identyfikator urządzenia: {deviceId}",
+        "nl": "Apparaat-ID: {deviceId}",
+        "ru": "Идентификатор устройства: {deviceId}"
       }
     },
     "approval_nearby_device": {
@@ -530,27 +530,27 @@
       }
     },
     "approval_request_body": {
-      "context": "Approval prompt body: '{arg1} wants to receive \"{arg2}\".' {arg1} = requester name, {arg2} = transfer name.",
+      "context": "Approval prompt body: '{receiver} wants to receive \"{transferName}\".' {receiver} = requester name, {transferName} = transfer name.",
       "args": [
         {
-          "name": "arg1",
+          "name": "receiver",
           "type": "string"
         },
         {
-          "name": "arg2",
+          "name": "transferName",
           "type": "string"
         }
       ],
       "translations": {
-        "en": "{arg1} wants to receive “{arg2}”.",
-        "fr": "{arg1} souhaite recevoir « {arg2} ».",
-        "es": "{arg1} quiere recibir «{arg2}».",
-        "it": "{arg1} vuole ricevere «{arg2}».",
-        "de": "{arg1} möchte „{arg2}“ empfangen.",
-        "pt": "{arg1} quer receber «{arg2}».",
-        "pl": "{arg1} chce odebrać „{arg2}”.",
-        "nl": "{arg1} wil ‘{arg2}’ ontvangen.",
-        "ru": "{arg1} хочет получить «{arg2}»."
+        "en": "{receiver} wants to receive “{transferName}”.",
+        "fr": "{receiver} souhaite recevoir « {transferName} ».",
+        "es": "{receiver} quiere recibir «{transferName}».",
+        "it": "{receiver} vuole ricevere «{transferName}».",
+        "de": "{receiver} möchte „{transferName}“ empfangen.",
+        "pt": "{receiver} quer receber «{transferName}».",
+        "pl": "{receiver} chce odebrać „{transferName}”.",
+        "nl": "{receiver} wil ‘{transferName}’ ontvangen.",
+        "ru": "{receiver} хочет получить «{transferName}»."
       }
     },
     "battery_level_title": {
@@ -2212,23 +2212,23 @@
       }
     },
     "receive_delete_history_description": {
-      "context": "Receive history: confirmation body for removing one item. {arg1} = transfer name.",
+      "context": "Receive history: confirmation body for removing one item. {transferName} = transfer name.",
       "args": [
         {
-          "name": "arg1",
+          "name": "transferName",
           "type": "string"
         }
       ],
       "translations": {
-        "en": "“{arg1}” will be removed from VniDrop’s history. The downloaded file will remain on this device.",
-        "fr": "« {arg1} » sera retiré de l’historique de VniDrop. Le fichier téléchargé restera sur cet appareil.",
-        "es": "«{arg1}» se eliminará del historial de VniDrop. El archivo descargado permanecerá en este dispositivo.",
-        "it": "«{arg1}» verrà rimosso dalla cronologia di VniDrop. Il file scaricato rimarrà su questo dispositivo.",
-        "de": "„{arg1}“ wird aus dem Verlauf von VniDrop entfernt. Die heruntergeladene Datei verbleibt auf diesem Gerät.",
-        "pt": "«{arg1}» será removido do histórico do VniDrop. O ficheiro descarregado permanecerá neste dispositivo.",
-        "pl": "„{arg1}” zostanie usunięty z historii VniDrop. Pobrany plik pozostanie na tym urządzeniu.",
-        "nl": "‘{arg1}’ wordt uit de geschiedenis van VniDrop verwijderd. Het gedownloade bestand blijft op dit apparaat.",
-        "ru": "«{arg1}» будет удалён из истории VniDrop. Загруженный файл останется на этом устройстве."
+        "en": "“{transferName}” will be removed from VniDrop’s history. The downloaded file will remain on this device.",
+        "fr": "« {transferName} » sera retiré de l’historique de VniDrop. Le fichier téléchargé restera sur cet appareil.",
+        "es": "«{transferName}» se eliminará del historial de VniDrop. El archivo descargado permanecerá en este dispositivo.",
+        "it": "«{transferName}» verrà rimosso dalla cronologia di VniDrop. Il file scaricato rimarrà su questo dispositivo.",
+        "de": "„{transferName}“ wird aus dem Verlauf von VniDrop entfernt. Die heruntergeladene Datei verbleibt auf diesem Gerät.",
+        "pt": "«{transferName}» será removido do histórico do VniDrop. O ficheiro descarregado permanecerá neste dispositivo.",
+        "pl": "„{transferName}” zostanie usunięty z historii VniDrop. Pobrany plik pozostanie na tym urządzeniu.",
+        "nl": "‘{transferName}’ wordt uit de geschiedenis van VniDrop verwijderd. Het gedownloade bestand blijft op dit apparaat.",
+        "ru": "«{transferName}» будет удалён из истории VniDrop. Загруженный файл останется на этом устройстве."
       }
     },
     "receive_delete_history_item": {
@@ -3148,23 +3148,23 @@
       }
     },
     "transfer_delete_description": {
-      "context": "Transfer details: confirmation body for deleting a transfer. {arg1} = transfer name.",
+      "context": "Transfer details: confirmation body for deleting a transfer. {transferName} = transfer name.",
       "args": [
         {
-          "name": "arg1",
+          "name": "transferName",
           "type": "string"
         }
       ],
       "translations": {
-        "en": "“{arg1}” will stop being shared and its transfer history will be removed from this device.",
-        "fr": "« {arg1} » cessera d’être partagé et son historique de transfert sera retiré de cet appareil.",
-        "es": "«{arg1}» dejará de compartirse y su historial de transferencia se eliminará de este dispositivo.",
-        "it": "«{arg1}» non verrà più condiviso e la sua cronologia di trasferimento verrà rimossa da questo dispositivo.",
-        "de": "„{arg1}“ wird nicht mehr geteilt und sein Übertragungsverlauf wird von diesem Gerät entfernt.",
-        "pt": "«{arg1}» deixará de ser partilhado e o seu histórico de transferência será removido deste dispositivo.",
-        "pl": "„{arg1}” przestanie być udostępniany, a jego historia transferu zostanie usunięta z tego urządzenia.",
-        "nl": "‘{arg1}’ wordt niet meer gedeeld en de overdrachtsgeschiedenis wordt van dit apparaat verwijderd.",
-        "ru": "Общий доступ к «{arg1}» будет остановлен, а история передачи будет удалена с этого устройства."
+        "en": "“{transferName}” will stop being shared and its transfer history will be removed from this device.",
+        "fr": "« {transferName} » cessera d’être partagé et son historique de transfert sera retiré de cet appareil.",
+        "es": "«{transferName}» dejará de compartirse y su historial de transferencia se eliminará de este dispositivo.",
+        "it": "«{transferName}» non verrà più condiviso e la sua cronologia di trasferimento verrà rimossa da questo dispositivo.",
+        "de": "„{transferName}“ wird nicht mehr geteilt und sein Übertragungsverlauf wird von diesem Gerät entfernt.",
+        "pt": "«{transferName}» deixará de ser partilhado e o seu histórico de transferência será removido deste dispositivo.",
+        "pl": "„{transferName}” przestanie być udostępniany, a jego historia transferu zostanie usunięta z tego urządzenia.",
+        "nl": "‘{transferName}’ wordt niet meer gedeeld en de overdrachtsgeschiedenis wordt van dit apparaat verwijderd.",
+        "ru": "Общий доступ к «{transferName}» будет остановлен, а история передачи будет удалена с этого устройства."
       }
     },
     "transfer_delete_title": {