fix(i18n,notice): make locale formatting idempotent and guard early notice translations

scripts/cleanup-unused-i18n.mjs

@@ -945,11 +945,16 @@ function loadLocales() {
 function ensureBackup(localePath) {
   const backupPath = `${localePath}.bak`;
   if (fs.existsSync(backupPath)) {
+    try {
+      fs.rmSync(backupPath);
+    } catch (error) {
       throw new Error(
-      `Backup file already exists for ${path.basename(localePath)}; ` +
+        `Failed to recycle existing backup for ${path.basename(
-        "either remove it manually or rerun with --no-backup",
+          localePath,
+        )}: ${error.message}`,
       );
     }
+  }
   fs.copyFileSync(localePath, backupPath);
   return backupPath;
 }
@@ -959,10 +964,27 @@ function backupIfNeeded(filePath, backups, options) {
   if (!fs.existsSync(filePath)) return;
   if (backups.has(filePath)) return;
   const backupPath = ensureBackup(filePath);
-  backups.add(filePath);
+  backups.set(filePath, backupPath);
   return backupPath;
 }
 
+function cleanupBackups(backups) {
+  for (const backupPath of backups.values()) {
+    try {
+      if (fs.existsSync(backupPath)) {
+        fs.rmSync(backupPath);
+      }
+    } catch (error) {
+      console.warn(
+        `Warning: failed to remove backup ${path.basename(
+          backupPath,
+        )}: ${error.message}`,
+      );
+    }
+  }
+  backups.clear();
+}
+
 function toModuleIdentifier(namespace, seen) {
   const RESERVED = new Set([
     "default",
@@ -1016,13 +1038,16 @@ export default resources;
 }
 
 function writeLocale(locale, data, options) {
-  const backups = new Set();
+  const backups = new Map();
+  let success = false;
 
+  try {
     if (locale.format === "single-file") {
       const target = locale.files[0].path;
       backupIfNeeded(target, backups, options);
       const serialized = JSON.stringify(data, null, 2);
       fs.writeFileSync(target, `${serialized}\n`, "utf8");
+      success = true;
       return;
     }
 
@@ -1056,6 +1081,12 @@ function writeLocale(locale, data, options) {
       namespace,
       path: path.join(locale.dir, `${namespace}.json`),
     }));
+    success = true;
+  } finally {
+    if (success) {
+      cleanupBackups(backups);
+    }
+  }
 }
 
 function processLocale(

src/services/noticeService.ts

@@ -44,6 +44,8 @@ const DEFAULT_DURATIONS: Readonly<Record<NoticeType, number>> = {
   error: 8000,
 };
 
+const TRANSLATION_KEY_PATTERN = /^[A-Za-z0-9_-]+(?:\.[A-Za-z0-9_-]+)+$/;
+
 let nextId = 0;
 let notices: NoticeItem[] = [];
 const subscribers: Set<NoticeSubscriber> = new Set();
@@ -157,11 +159,16 @@ function createRawDescriptor(message: string): NoticeTranslationDescriptor {
   };
 }
 
+function isLikelyTranslationKey(key: string) {
+  return TRANSLATION_KEY_PATTERN.test(key);
+}
+
 function shouldUseTranslationKey(
   key: string,
   params?: Record<string, unknown>,
 ) {
   if (params && Object.keys(params).length > 0) return true;
+  if (isLikelyTranslationKey(key)) return true;
   if (i18n.isInitialized) {
     return i18n.exists(key);
   }