diff --git a/frontend/src/App.css b/frontend/src/App.css
index c72aab078..84a4209a3 100644
--- a/frontend/src/App.css
+++ b/frontend/src/App.css
@@ -533,11 +533,15 @@
   outline: none;
 }
 
-.lineage-dag-node:focus circle,
 .lineage-dag-node:hover circle {
   stroke-width: 2.5;
 }
 
+.lineage-dag-node:focus circle {
+  stroke: var(--color-focus-border);
+  stroke-width: 3.5;
+}
+
 .lineage-dag-node[aria-current="true"] circle {
   stroke-width: 3;
   stroke: var(--text-h);
diff --git a/frontend/src/App.tsx b/frontend/src/App.tsx
index 86a1e9b26..ac94a88c4 100644
--- a/frontend/src/App.tsx
+++ b/frontend/src/App.tsx
@@ -352,6 +352,7 @@ function ChatPanel({
             onChange={(event) => setQuestion(event.target.value)}
             onKeyDown={(event) => event.key === "Enter" && handleAsk()}
             placeholder={t("What happened between these events?")}
+            aria-label={t("What happened between these events?")}
           />
           <button onClick={() => handleAsk()} disabled={loading || !question.trim()}>
             {loading ? t("Asking...") : t("Ask")}
@@ -386,7 +387,7 @@ function ChatPanel({
           ))}
         </div>
       )}
-      {error && <p className="error">{error}</p>}
+      {error && <p className="error" role="alert">{error}</p>}
       {exchanges
         .filter(
           (exchange) =>
@@ -1167,7 +1168,7 @@ function KeymanPanel({
           </details>
         )}
       </div>
-      {error && <p className="error">{error}</p>}
+      {error && <p className="error" role="alert">{error}</p>}
       {sourceAuthorContext ? (
         <details className="keyman-source-context">
           <summary>{t("Source author evidence")} · {t("Hint only")}</summary>
@@ -1339,7 +1340,7 @@ function EvaluationPanel({
           </details>
         )}
       </div>
-      {error && <p className="error">{error}</p>}
+      {error && <p className="error" role="alert">{error}</p>}
       {responses === null ? (
         <p>{t("Loading evaluation...")}</p>
       ) : responses.length === 0 ? (
@@ -1413,7 +1414,7 @@ function CounterpartyPanel({
           </details>
         )}
       </div>
-      {error && <p className="error">{error}</p>}
+      {error && <p className="error" role="alert">{error}</p>}
       <ul>
         {counterparties.map((c) => (
           <li key={c.counterparty_entity_name}>
@@ -1556,7 +1557,7 @@ function IssueTicketPanel({
           </details>
         )}
       </div>
-      {error && <p className="error">{error}</p>}
+      {error && <p className="error" role="alert">{error}</p>}
       {tickets === null ? (
         <p>{t("Loading tickets...")}</p>
       ) : tickets.length === 0 ? (
@@ -1591,6 +1592,7 @@ function IssueTicketPanel({
           onChange={(event) => setNewTitle(event.target.value)}
           onKeyDown={(event) => event.key === "Enter" && handleCreate()}
           placeholder={t("New ticket title")}
+          aria-label={t("New ticket title")}
         />
         <input
           type="date"
@@ -1644,7 +1646,7 @@ function ActivityPanel({ postId, accessToken }: { postId: string; accessToken: s
         <h3>{t("Activity")}</h3>
         <button onClick={reload}>{t("Refresh")}</button>
       </div>
-      {error && <p className="error">{error}</p>}
+      {error && <p className="error" role="alert">{error}</p>}
       {events === null ? (
         <p>{t("Loading activity...")}</p>
       ) : events.length === 0 ? (
@@ -1885,7 +1887,7 @@ function PostDetailPopup({
     <div className="popup-backdrop" onClick={onClose}>
       <div className="popup-panel" onClick={(event) => event.stopPropagation()}>
         <PopupCloseButton onClose={onClose} label={t("Close")} />
-        {error && <p className="error">{error}</p>}
+        {error && <p className="error" role="alert">{error}</p>}
         {!post && !error && <p>{t("Loading...")}</p>}
         {post && (
           <>
@@ -2263,7 +2265,7 @@ function PostDetailPopup({
                   )}
                 </>
               ) : summaryError ? (
-                <p className="error">{summaryError}</p>
+                <p className="error" role="alert">{summaryError}</p>
               ) : (
                 <p className="popup-placeholder">{t("No summary is available for this record yet.")}</p>
               )}
@@ -2835,7 +2837,7 @@ function AnalysisRunsPanel({
     }
   }
 
-  if (error && runs === null) return <p className="error">{error}</p>;
+  if (error && runs === null) return <p className="error" role="alert">{error}</p>;
   if (runs === null) return <p>Loading analysis runs...</p>;
 
   const corpusHint = selected ? analysisRunCorpusHint(selected) : null;
@@ -2864,7 +2866,7 @@ function AnalysisRunsPanel({
           {requestLabel}
         </button>
       </div>
-      {(error || entitiesLoadError) && <p className="error">{error ?? entitiesLoadError}</p>}
+      {(error || entitiesLoadError) && <p className="error" role="alert">{error ?? entitiesLoadError}</p>}
       {runs.length === 0 ? (
         <p className="popup-placeholder">
           No analysis runs visible to this account yet. Request a lineage
@@ -3086,7 +3088,7 @@ function RankingsPanel({
           </span>
         )}
       </div>
-      {error && <p className="error">{error}</p>}
+      {error && <p className="error" role="alert">{error}</p>}
       {ranking === null && !error && <p>Loading rankings...</p>}
       {ranking && ranking.status === "unavailable" && (
         <p className="popup-placeholder">Rankings · RankWeave not available</p>
@@ -3131,7 +3133,7 @@ function CalendarPanel({
       .catch((err) => setError(String(err)));
   }, [accessToken]);
 
-  if (error) return <p className="error">{error}</p>;
+  if (error) return <p className="error" role="alert">{error}</p>;
   if (calendar === null) return <p>{t("Loading calendar...")}</p>;
 
   const events = calendar.events ?? [];
@@ -3560,7 +3562,7 @@ function ReportsPanel({
           ))}
         </ul>
       )}
-      {error && <p className="error">{error}</p>}
+      {error && <p className="error" role="alert">{error}</p>}
       {!openedGroupingLabel && reportList}
     </section>
   );
@@ -4025,7 +4027,7 @@ function PostList({
                   {rebuilding ? t("Rebuilding...") : t("Rebuild lineage")}
                 </button>
               </div>
-              {rebuildError && <p className="error">{rebuildError}</p>}
+              {rebuildError && <p className="error" role="alert">{rebuildError}</p>}
             </section>
           )}
           <CalendarPanel accessToken={accessToken} onSelectPost={selectPost} />
@@ -4297,7 +4299,7 @@ function CustomerMasterPanel({
       <p className="section-eyebrow">{t("Authorized customer scope")}</p>
       <h2 id="customer-master-heading">{t("Customer master")}</h2>
       <p className="buyer-destination-intro">{t("Customer entities available to this account.")}</p>
-      {error ? <p className="error">{error}</p> : null}
+      {error ? <p className="error" role="alert">{error}</p> : null}
       {master === null && !error ? <p>{t("Loading customer master...")}</p> : null}
       {master?.corporate_entities.length === 0 ? (
         <p className="popup-placeholder">{t("No customer entities are connected to this account.")}</p>
@@ -4355,7 +4357,7 @@ function CustomerMasterPanel({
               })}
             </p>
           )}
-          {resolveError ? <p className="error">{resolveError}</p> : null}
+          {resolveError ? <p className="error" role="alert">{resolveError}</p> : null}
           <ul className="customer-master-list">
             {master.source_customer_hints.slice(0, HINT_RENDER_LIMIT).map((hint) => (
               <li key={`${hint.customer_code ?? "name"}:${hint.customer_name ?? "unknown"}`}>
@@ -4498,7 +4500,7 @@ function AskAgentPanel({
       <p className="section-eyebrow">{t("Evidence-grounded questions")}</p>
       <h2 id="ask-agent-heading">{t("Ask Agent")}</h2>
       <p className="buyer-destination-intro">{t("Questions use authorized posts and their evidence.")}</p>
-      {error ? <p className="error">{error}</p> : null}
+      {error ? <p className="error" role="alert">{error}</p> : null}
       <label className="ask-agent-source">
         <span>{t("Ask a question")}</span>
         <textarea
@@ -4638,7 +4640,7 @@ export default function App({ showLabPanels = false }: { showLabPanels?: boolean
   }
 
   if (!accessToken) {
-    return <p className="error">{t("Authenticated, but no access token was returned.")}</p>;
+    return <p className="error" role="alert">{t("Authenticated, but no access token was returned.")}</p>;
   }
 
   return (
diff --git a/frontend/src/components/AdminPanel.tsx b/frontend/src/components/AdminPanel.tsx
index af098f827..fe82cdf7d 100644
--- a/frontend/src/components/AdminPanel.tsx
+++ b/frontend/src/components/AdminPanel.tsx
@@ -54,8 +54,16 @@ export function AdminPanel({ currentBrandName, onBrandNameChange, accessToken }:
           <button type="submit" className="btn-primary" disabled={saving || !draftName.trim() || draftName === currentBrandName}>
             {saving ? t("Saving...") : t("Save settings")}
           </button>
-          {saved && <span style={{ marginLeft: "1rem", color: "green" }}>{t("Settings saved!")}</span>}
-          {error && <span style={{ marginLeft: "1rem", color: "red" }}>{t(error)}</span>}
+          {saved && (
+            <span role="status" style={{ marginLeft: "1rem", color: "green" }}>
+              {t("Settings saved!")}
+            </span>
+          )}
+          {error && (
+            <span role="alert" style={{ marginLeft: "1rem", color: "red" }}>
+              {t(error)}
+            </span>
+          )}
         </div>
       </form>
     </div>
diff --git a/frontend/src/i18n.test.ts b/frontend/src/i18n.test.ts
index 5a3afbfc3..3877288c3 100644
--- a/frontend/src/i18n.test.ts
+++ b/frontend/src/i18n.test.ts
@@ -3,6 +3,7 @@ import {
   LOCALE_LABELS,
   SUPPORTED_LOCALES,
   getLocale,
+  localeKeys,
   setLocale,
   t,
   tf,
@@ -76,6 +77,22 @@ describe("i18n", () => {
   });
 });
 
+describe("locale key parity", () => {
+  it("registers the same translation keys in every non-English locale block", () => {
+    // A key present in one locale but silently missing from another falls
+    // back to the raw English key text (or an untranslated aria-label) at
+    // runtime with no build-time signal -- this caught exactly that for
+    // "Affiliates of {name}" (2026-08-23).
+    const locales = ["ko", "zh", "ja", "vi"] as const;
+    const keySets = locales.map((locale) => new Set(localeKeys(locale)));
+    const union = new Set(keySets.flatMap((set) => [...set]));
+    for (const [index, locale] of locales.entries()) {
+      const missing = [...union].filter((key) => !keySets[index].has(key));
+      expect(missing, `${locale} is missing keys: ${missing.join(", ")}`).toEqual([]);
+    }
+  });
+});
+
 describe("locale-aware source labels", () => {
   it.each([
     ["en", "Voice of Customer", "Public"],
diff --git a/frontend/src/i18n.ts b/frontend/src/i18n.ts
index 650acfca8..9eccfa527 100644
--- a/frontend/src/i18n.ts
+++ b/frontend/src/i18n.ts
@@ -241,6 +241,7 @@ const TRANSLATIONS: Partial<Record<Locale, Record<string, string>>> = {
     "No tickets yet.": "아직 티켓이 없습니다.",
     "New ticket title": "새 티켓 제목",
     "Due date": "기한",
+    "Affiliates of {name}": "{name}의 계열사",
     "Create ticket": "티켓 작성",
     "Loading activity...": "활동을 불러오는 중...",
     "No activity yet.": "아직 활동이 없습니다.",
@@ -580,6 +581,7 @@ const TRANSLATIONS: Partial<Record<Locale, Record<string, string>>> = {
     "No tickets yet.": "暂时没有工单。",
     "New ticket title": "新工单标题",
     "Due date": "截止日期",
+    "Affiliates of {name}": "{name}的关联公司",
     "Create ticket": "创建工单",
     "Loading activity...": "正在加载活动...",
     "No activity yet.": "暂时没有活动。",
@@ -933,6 +935,7 @@ const TRANSLATIONS: Partial<Record<Locale, Record<string, string>>> = {
     "No tickets yet.": "チケットはまだありません。",
     "New ticket title": "新しいチケットのタイトル",
     "Due date": "期限",
+    "Affiliates of {name}": "{name}の関連会社",
     "Create ticket": "チケットを作成",
     "Loading activity...": "アクティビティを読み込んでいます...",
     "No activity yet.": "アクティビティはまだありません。",
@@ -1271,6 +1274,7 @@ const TRANSLATIONS: Partial<Record<Locale, Record<string, string>>> = {
     "No tickets yet.": "Chưa có phiếu công việc.",
     "New ticket title": "Tiêu đề phiếu mới",
     "Due date": "Hạn hoàn thành",
+    "Affiliates of {name}": "Công ty liên kết của {name}",
     "Create ticket": "Tạo phiếu công việc",
     "Loading activity...": "Đang tải hoạt động...",
     "No activity yet.": "Chưa có hoạt động.",
@@ -1404,6 +1408,11 @@ export function getLocale(): Locale {
   return currentLocale;
 }
 
+/** Registered translation keys for one locale block -- for cross-locale parity checks. */
+export function localeKeys(locale: Locale): string[] {
+  return Object.keys(TRANSLATIONS[locale] ?? {});
+}
+
 export function setLocale(locale: Locale): void {
   if (!SUPPORTED_LOCALES.includes(locale) || locale === currentLocale) return;
   currentLocale = locale;