fix(ci): retry locale placeholder mismatches

scripts/control-ui-i18n.ts

@@ -12,6 +12,7 @@ import {
   compareStringArrays,
   createControlUiLocaleSyncPlan,
   flattenTranslations,
+  resolveLocaleMetaProvenance,
   type GlossaryEntry,
   type LocaleEntry,
   type LocaleMeta,
@@ -1317,6 +1318,24 @@ function parseTranslationReply(raw: string): Record<string, unknown> {
   return JSON.parse(fenced ? fenced[1] : trimmed) as Record<string, unknown>;
 }
 
+export function parseTranslationBatchReply(
+  raw: string,
+  items: readonly TranslationBatchItem[],
+  locale: string,
+): Map<string, string> {
+  const parsed = parseTranslationReply(raw);
+  const translated = new Map<string, string>();
+  for (const item of items) {
+    const value = parsed[item.key];
+    if (typeof value !== "string" || !value.trim()) {
+      throw new Error(`missing translation for ${item.key}`);
+    }
+    translated.set(item.key, value);
+  }
+  assertPlaceholderParity(new Map(items.map((item) => [item.key, item.text])), translated, locale);
+  return translated;
+}
+
 async function translateBatch(
   clientAccess: ClientAccess,
   items: readonly TranslationBatchItem[],
@@ -1334,15 +1353,7 @@ async function translateBatch(
       const raw = await (
         await clientAccess.getClient()
       ).prompt(buildBatchPrompt(items), attemptLabel);
-      const parsed = parseTranslationReply(raw);
-      const translated = new Map<string, string>();
-      for (const item of items) {
-        const value = parsed[item.key];
-        if (typeof value !== "string" || !value.trim()) {
-          throw new Error(`missing translation for ${item.key}`);
-        }
-        translated.set(item.key, value);
-      }
+      const translated = parseTranslationBatchReply(raw, items, context.locale);
       logProgress(`${attemptLabel}: done (${formatDuration(Date.now() - startedAt)})`);
       return translated;
     } catch (error) {
@@ -1528,16 +1539,18 @@ async function syncLocale(
   // legitimately stay identical to English. Track fallback keys from actual
   // fallback decisions and previous fallback metadata instead.
 
-  const nextProvider = allowTranslate
-    ? resolveConfiguredProvider()
-    : (previousMeta?.provider ?? "");
-  const nextModel = allowTranslate ? resolveConfiguredModel() : (previousMeta?.model ?? "");
+  const provenance = resolveLocaleMetaProvenance({
+    didTranslate: allowTranslate && plan.pending.length > 0,
+    model: allowTranslate ? resolveConfiguredModel() : "",
+    previousMeta,
+    provider: allowTranslate ? resolveConfiguredProvider() : "",
+  });
   const artifacts = plan.render({
     defaultGlossary: DEFAULT_GLOSSARY,
     generatedAt: new Date().toISOString(),
     glossary,
-    model: nextModel,
-    provider: nextProvider,
+    model: provenance.model,
+    provider: provenance.provider,
     workflow: CONTROL_UI_I18N_WORKFLOW,
   });
   assertPlaceholderParity(sourceFlat, artifacts.nextFlat, entry.locale);

scripts/lib/control-ui-i18n-sync-plan.ts

@@ -71,6 +71,21 @@ export function shouldReuseExistingTranslation(options: {
   return !options.isFallback || (!options.allowTranslate && !options.force);
 }
 
+export function resolveLocaleMetaProvenance(options: {
+  didTranslate: boolean;
+  model: string;
+  previousMeta: LocaleMeta | null;
+  provider: string;
+}): { model: string; provider: string } {
+  if (options.didTranslate) {
+    return { model: options.model, provider: options.provider };
+  }
+  return {
+    model: options.previousMeta?.model ?? options.model,
+    provider: options.previousMeta?.provider ?? options.provider,
+  };
+}
+
 export function createControlUiLocaleSyncPlan(input: {
   allowTranslate: boolean;
   cacheKeyFor: (key: string, textHash: string) => string;

test/scripts/control-ui-i18n-sync-plan.test.ts

@@ -2,6 +2,7 @@ import { describe, expect, it } from "vitest";
 import {
   createControlUiLocaleSyncPlan,
   flattenTranslations,
+  resolveLocaleMetaProvenance,
   type LocaleEntry,
   type LocaleMeta,
   type TranslationMemoryEntry,
@@ -50,6 +51,27 @@ function localeMeta(overrides: Partial<LocaleMeta> = {}): LocaleMeta {
 }
 
 describe("createControlUiLocaleSyncPlan", () => {
+  it("preserves provenance when a configured provider performs no translation", () => {
+    const previousMeta = localeMeta();
+
+    expect(
+      resolveLocaleMetaProvenance({
+        didTranslate: false,
+        model: "next-model",
+        previousMeta,
+        provider: "next-provider",
+      }),
+    ).toEqual({ model: previousMeta.model, provider: previousMeta.provider });
+    expect(
+      resolveLocaleMetaProvenance({
+        didTranslate: true,
+        model: "next-model",
+        previousMeta,
+        provider: "next-provider",
+      }),
+    ).toEqual({ model: "next-model", provider: "next-provider" });
+  });
+
   it("plans reuse and renders deterministic locale artifacts", () => {
     const sourceFlat = flattenTranslations({
       group: {

test/scripts/control-ui-i18n.test.ts

@@ -7,6 +7,7 @@ import { pathToFileURL } from "node:url";
 import { describe, expect, it } from "vitest";
 import {
   appendBoundedProcessOutput,
+  parseTranslationBatchReply,
   runProcess,
   shouldReuseExistingTranslation,
 } from "../../scripts/control-ui-i18n.ts";
@@ -50,6 +51,32 @@ async function waitForChildClose(
 }
 
 describe("control-ui-i18n process runner", () => {
+  it("rejects placeholder-corrupt batch replies before they leave the retry loop", () => {
+    const items = [
+      {
+        cacheKey: "cache-key",
+        key: "configView.viewPendingChange",
+        text: "View pending change ({count})",
+        textHash: "text-hash",
+      },
+    ];
+
+    expect(() =>
+      parseTranslationBatchReply(
+        JSON.stringify({ "configView.viewPendingChange": "Pending change" }),
+        items,
+        "ar",
+      ),
+    ).toThrow("ar:configView.viewPendingChange expected {count} got {}");
+    expect(
+      parseTranslationBatchReply(
+        JSON.stringify({ "configView.viewPendingChange": "Pending change ({count})" }),
+        items,
+        "ar",
+      ),
+    ).toEqual(new Map([["configView.viewPendingChange", "Pending change ({count})"]]));
+  });
+
   it("ships no recorded English fallbacks", () => {
     const metaDir = path.resolve("ui/src/i18n/.i18n");
     const fallbacks = readdirSync(metaDir)