diff --git a/plugins/browser-inbox/frontend/src/index.js b/plugins/browser-inbox/frontend/src/index.js
index afa36c6..2091422 100644
--- a/plugins/browser-inbox/frontend/src/index.js
+++ b/plugins/browser-inbox/frontend/src/index.js
@@ -1059,7 +1059,7 @@
 
       function loadPairing() {
         setBusy(true);
-        setStatus('Loading...', false);
+        setStatus(tr('ui.loading', null, 'Loading...'), false);
         return Promise.resolve().then(function () {
           return pairingAPI().pairing();
         }).then(function (pairing) {
@@ -1075,11 +1075,11 @@
       function copyValue(value, label) {
         if (!value) return;
         if (typeof navigator === 'undefined' || !navigator.clipboard || typeof navigator.clipboard.writeText !== 'function') {
-          setStatus('Clipboard unavailable', true);
+          setStatus(tr('ui.clipboardUnavailable', null, 'Clipboard unavailable'), true);
           return;
         }
         navigator.clipboard.writeText(value).then(function () {
-          setStatus(label + ' copied', false);
+          setStatus(tr('ui.copied', { label: label }, '{label} copied'), false);
         }).catch(function (err) {
           setStatus(text(err && err.message ? err.message : err), true);
         });
@@ -1092,14 +1092,14 @@
         copyValue(receiverTokenInput.value, 'Token');
       });
       rotateTokenButton.addEventListener('click', function () {
-        if (typeof window.confirm === 'function' && !window.confirm('Rotate pairing token?')) return;
+        if (typeof window.confirm === 'function' && !window.confirm(tr('ui.rotateConfirm', null, 'Rotate pairing token?'))) return;
         setBusy(true);
-        setStatus('Rotating...', false);
+        setStatus(tr('ui.rotating', null, 'Rotating...'), false);
         Promise.resolve().then(function () {
           return pairingAPI().rotateToken();
         }).then(function (pairing) {
           applyPairing(pairing);
-          setStatus('Token rotated', false);
+          setStatus(tr('ui.tokenRotated', null, 'Token rotated'), false);
         }).catch(function (err) {
           setStatus(text(err && err.message ? err.message : err), true);
         }).then(function () {
diff --git a/plugins/browser-inbox/locales/en.json b/plugins/browser-inbox/locales/en.json
index 303cc04..84456c6 100644
--- a/plugins/browser-inbox/locales/en.json
+++ b/plugins/browser-inbox/locales/en.json
@@ -29,5 +29,11 @@
   "ui.copyToken": "Copy Token",
   "ui.rotateToken": "Rotate Token",
   "ui.receiverUrl": "Receiver URL",
-  "ui.pairingToken": "Pairing Token"
+  "ui.pairingToken": "Pairing Token",
+  "ui.loading": "Loading...",
+  "ui.clipboardUnavailable": "Clipboard unavailable",
+  "ui.copied": "{label} copied",
+  "ui.rotateConfirm": "Rotate pairing token?",
+  "ui.rotating": "Rotating...",
+  "ui.tokenRotated": "Token rotated"
 }
diff --git a/plugins/browser-inbox/locales/ru.json b/plugins/browser-inbox/locales/ru.json
index 4c497b3..3cb6de2 100644
--- a/plugins/browser-inbox/locales/ru.json
+++ b/plugins/browser-inbox/locales/ru.json
@@ -29,5 +29,11 @@
   "ui.copyToken": "Копировать токен",
   "ui.rotateToken": "Сменить токен",
   "ui.receiverUrl": "URL приёмника",
-  "ui.pairingToken": "Токен сопряжения"
+  "ui.pairingToken": "Токен сопряжения",
+  "ui.loading": "Загрузка...",
+  "ui.clipboardUnavailable": "Буфер обмена недоступен",
+  "ui.copied": "{label} скопирован",
+  "ui.rotateConfirm": "Сменить токен сопряжения?",
+  "ui.rotating": "Смена токена...",
+  "ui.tokenRotated": "Токен изменён"
 }
diff --git a/plugins/journal/frontend/src/index.js b/plugins/journal/frontend/src/index.js
index 83917f8..30452f6 100644
--- a/plugins/journal/frontend/src/index.js
+++ b/plugins/journal/frontend/src/index.js
@@ -505,7 +505,11 @@
     }
 
     function render() {
-      countEl.textContent = entries.length + ' entr' + (entries.length === 1 ? 'y' : 'ies');
+      countEl.textContent = tr(
+        entries.length === 1 ? 'ui.entryCount.one' : 'ui.entryCount.many',
+        { count: entries.length },
+        entries.length === 1 ? '{count} entry' : '{count} entries'
+      );
       statusEl.textContent = statusText;
       statusEl.className = 'journal-status' + (statusClass ? ' ' + statusClass : '');
       addBtn.disabled = scope.mode !== 'workspace';
diff --git a/plugins/journal/locales/en.json b/plugins/journal/locales/en.json
index 629c5cc..4c74be4 100644
--- a/plugins/journal/locales/en.json
+++ b/plugins/journal/locales/en.json
@@ -29,5 +29,7 @@
   "ui.deleted": "Entry deleted",
   "ui.empty": "No worklog entries yet.",
   "ui.edit": "Edit",
-  "ui.delete": "Delete"
+  "ui.delete": "Delete",
+  "ui.entryCount.one": "{count} entry",
+  "ui.entryCount.many": "{count} entries"
 }
diff --git a/plugins/journal/locales/ru.json b/plugins/journal/locales/ru.json
index 12dd97a..6f955bf 100644
--- a/plugins/journal/locales/ru.json
+++ b/plugins/journal/locales/ru.json
@@ -29,5 +29,7 @@
   "ui.deleted": "Запись удалена",
   "ui.empty": "Записей о работе пока нет.",
   "ui.edit": "Изменить",
-  "ui.delete": "Удалить"
+  "ui.delete": "Удалить",
+  "ui.entryCount.one": "{count} запись",
+  "ui.entryCount.many": "Записей: {count}"
 }
diff --git a/plugins/platform-test/frontend/src/index.js b/plugins/platform-test/frontend/src/index.js
index 61d7b8d..4fb0204 100644
--- a/plugins/platform-test/frontend/src/index.js
+++ b/plugins/platform-test/frontend/src/index.js
@@ -69,6 +69,13 @@
         return fallback || key;
       }
       containerEl.__ptCleanup = [];
+      var localizedNodes = [];
+
+      function localized(tag, attrs, key, fallback) {
+        var node = el(tag, attrs, [tr(key, null, fallback)]);
+        localizedNodes.push({ node: node, key: key, fallback: fallback });
+        return node;
+      }
 
       function trackCleanup(fn) {
         if (typeof fn === 'function') {
@@ -79,12 +86,19 @@
           containerEl.__ptCleanup.push(fn);
         }
       }
+      if (api.i18n && typeof api.i18n.onDidChangeLocale === 'function') {
+        trackCleanup(api.i18n.onDidChangeLocale(function () {
+          localizedNodes.forEach(function (item) {
+            item.node.textContent = tr(item.key, null, item.fallback);
+          });
+        }));
+      }
 
       /* ── Header ─────────────────────────────────────────────────── */
       var header = div('pt-header', [
         span('pt-icon', '◉'),
         div('pt-title-group', [
-          el('h2', { className: 'pt-plugin-name' }, [tr('ui.diagnostics', null, 'Platform Diagnostics')]),
+          localized('h2', { className: 'pt-plugin-name' }, 'ui.diagnostics', 'Platform Diagnostics'),
           el('p', { className: 'pt-plugin-id' }, [api.pluginId]),
         ]),
         span('pt-version', 'v' + (props && props.version ? props.version : '0.1.0')),
@@ -93,7 +107,7 @@
       /* ── Status badge ──────────────────────────────────────────── */
       var badge = div('pt-badge pt-badge-success', [
         el('span', {}, ['✅']),
-        el('span', {}, [tr('ui.bundleLoaded', null, 'Frontend Bundle Loaded')]),
+        localized('span', {}, 'ui.bundleLoaded', 'Frontend Bundle Loaded'),
       ]);
       var badgeRow = div('', [badge]);
 
@@ -279,7 +293,7 @@
         });
 
       var bridgeCard = div('pt-card', [
-        el('h3', { className: 'pt-card-title' }, [tr('ui.apiBridge', null, 'Real Plugin API Bridge')]),
+        localized('h3', { className: 'pt-card-title' }, 'ui.apiBridge', 'Real Plugin API Bridge'),
         el('ul', { className: 'pt-list' }, [
           el('li', { className: 'pt-list-item' }, [
             span('pt-list-label', 'Persisted setting'),
@@ -366,7 +380,7 @@
       });
 
       var testsCard = div('pt-card', [
-        el('h3', { className: 'pt-card-title' }, [tr('ui.testResults', null, 'Test Results')]),
+        localized('h3', { className: 'pt-card-title' }, 'ui.testResults', 'Test Results'),
         summaryRow,
         testsList,
       ]);
@@ -403,7 +417,7 @@
       });
 
       var capsCard = div('pt-card', [
-        el('h3', { className: 'pt-card-title' }, [tr('ui.capabilities', null, 'Registered Capabilities')]),
+        localized('h3', { className: 'pt-card-title' }, 'ui.capabilities', 'Registered Capabilities'),
         capList,
       ]);
 
@@ -426,7 +440,7 @@
       });
 
       var infoCard = div('pt-card', [
-        el('h3', { className: 'pt-card-title' }, [tr('ui.pluginInfo', null, 'Plugin Info')]),
+        localized('h3', { className: 'pt-card-title' }, 'ui.pluginInfo', 'Plugin Info'),
         infoList,
       ]);
 
@@ -461,7 +475,7 @@
       });
 
       var apiCard = div('pt-card', [
-        el('h3', { className: 'pt-card-title' }, [tr('ui.hostMethods', null, 'Host API Methods')]),
+        localized('h3', { className: 'pt-card-title' }, 'ui.hostMethods', 'Host API Methods'),
         apiStatusList,
       ]);
 
@@ -589,7 +603,7 @@
       trackCleanup(function () { stopMouseCapture(); });
 
       var mouseCard = div('pt-card', [
-        el('h3', { className: 'pt-card-title' }, [tr('ui.mouseInspector', null, 'Mouse Event Inspector')]),
+        localized('h3', { className: 'pt-card-title' }, 'ui.mouseInspector', 'Mouse Event Inspector'),
         el('p', { style: { margin: '0 0 0.5rem', color: '#a0a0b8', fontSize: '0.8rem' } }, [
           'Captures ALL mouse/pointer events on window. Press back/forward buttons to see what WebKitGTK reports.',
         ]),
@@ -676,6 +690,23 @@
         if (api && api.i18n && typeof api.i18n.t === 'function') return api.i18n.t(key, params, fallback);
         return fallback || key;
       }
+      var localizedNodes = [];
+      var unsubscribeLocale = null;
+
+      function localized(tag, attrs, key, fallback) {
+        var node = el(tag, attrs, [tr(key, null, fallback)]);
+        localizedNodes.push({ node: node, key: key, fallback: fallback });
+        return node;
+      }
+
+      if (api.i18n && typeof api.i18n.onDidChangeLocale === 'function') {
+        unsubscribeLocale = api.i18n.onDidChangeLocale(function () {
+          localizedNodes.forEach(function (item) {
+            item.node.textContent = tr(item.key, null, item.fallback);
+          });
+        });
+        containerEl.__ptSettingsCleanup = unsubscribeLocale;
+      }
 
       /* ── Counter state (local, not persisted) ──────────────────── */
       var counterState = { value: 0 };
@@ -684,7 +715,7 @@
       var header = div('pt-header', [
         span('pt-icon', '⚙️'),
         div('pt-title-group', [
-          el('h2', { className: 'pt-plugin-name' }, [tr('ui.settings', null, 'Platform Test Settings')]),
+          localized('h2', { className: 'pt-plugin-name' }, 'ui.settings', 'Platform Test Settings'),
           el('p', { className: 'pt-plugin-id' }, [api.pluginId]),
         ]),
       ]);
@@ -707,24 +738,24 @@
       var incrementBtn = el('button', { className: 'btn btn-primary', onClick: function () {
         counterState.value += 1;
         counterDisplay.firstChild.textContent = String(counterState.value);
-      }}, [tr('ui.increment', null, '+ Increment')]);
+      }}, [localized('span', {}, 'ui.increment', '+ Increment')]);
 
       var decrementBtn = el('button', { className: 'btn btn-secondary', onClick: function () {
         counterState.value = Math.max(0, counterState.value - 1);
         counterDisplay.firstChild.textContent = String(counterState.value);
-      }}, [tr('ui.decrement', null, '− Decrement')]);
+      }}, [localized('span', {}, 'ui.decrement', '− Decrement')]);
 
       var resetBtn = el('button', { className: 'btn btn-secondary', onClick: function () {
         counterState.value = 0;
         counterDisplay.firstChild.textContent = '0';
-      }}, [tr('ui.reset', null, '↺ Reset')]);
+      }}, [localized('span', {}, 'ui.reset', '↺ Reset')]);
 
       var btnGroup = el('div', { style: { display: 'flex', gap: '0.5rem' } }, [
         incrementBtn, decrementBtn, resetBtn,
       ]);
 
       var counterCard = div('pt-card', [
-        el('h3', { className: 'pt-card-title' }, [tr('ui.counter', null, 'Interactive Counter (Local State)')]),
+        localized('h3', { className: 'pt-card-title' }, 'ui.counter', 'Interactive Counter (Local State)'),
         counterDisplay,
         btnGroup,
         el('p', { style: { marginTop: '0.75rem', color: '#6c6c8a', fontSize: '0.7rem' } }, [
@@ -750,7 +781,7 @@
       });
 
       var settingsCard = div('pt-card', [
-        el('h3', { className: 'pt-card-title' }, [tr('ui.demoSettings', null, 'Plugin Settings (Demo)')]),
+        localized('h3', { className: 'pt-card-title' }, 'ui.demoSettings', 'Plugin Settings (Demo)'),
         settingsDemoList,
         el('p', { style: { marginTop: '0.5rem', color: '#6c6c8a', fontSize: '0.7rem' } }, [
           'Use api.settings.read() / api.settings.write() for persisted settings.',
@@ -765,8 +796,10 @@
     },
 
     unmount: function (containerEl) {
+      if (typeof containerEl.__ptSettingsCleanup === 'function') containerEl.__ptSettingsCleanup();
       containerEl.innerHTML = '';
       containerEl.className = '';
+      delete containerEl.__ptSettingsCleanup;
     },
   };
 
diff --git a/plugins/secrets/frontend/src/index.js b/plugins/secrets/frontend/src/index.js
index af08c68..df17129 100644
--- a/plugins/secrets/frontend/src/index.js
+++ b/plugins/secrets/frontend/src/index.js
@@ -423,7 +423,7 @@
       }
 
       function deleteSecret(id) {
-        if (!id || !window.confirm('Delete this secret?')) return;
+        if (!id || !window.confirm(tr('ui.deleteConfirm', null, 'Delete this secret?'))) return;
         api.secrets.delete(id).then(function () {
           selectedID = '';
           selectedRecord = null;
@@ -437,7 +437,7 @@
       function copySecretLink(id) {
         api.secrets.copyLink(id).then(function (link) {
           return writeClipboard(api, link).then(function () {
-            setStatus('Secret link copied', false);
+            setStatus(tr('ui.linkCopied', null, 'Secret link copied'), false);
           });
         }).catch(function (err) {
           setStatus((err && err.message) ? err.message : String(err), true);
diff --git a/plugins/secrets/locales/en.json b/plugins/secrets/locales/en.json
index 352516e..1e4b70c 100644
--- a/plugins/secrets/locales/en.json
+++ b/plugins/secrets/locales/en.json
@@ -32,5 +32,7 @@
   "ui.scope": "Scope",
   "ui.value": "Value",
   "ui.save": "Save",
-  "ui.cancel": "Cancel"
+  "ui.cancel": "Cancel",
+  "ui.deleteConfirm": "Delete this secret?",
+  "ui.linkCopied": "Secret link copied"
 }
diff --git a/plugins/secrets/locales/ru.json b/plugins/secrets/locales/ru.json
index ab19dda..1a34bf5 100644
--- a/plugins/secrets/locales/ru.json
+++ b/plugins/secrets/locales/ru.json
@@ -32,5 +32,7 @@
   "ui.scope": "Область",
   "ui.value": "Значение",
   "ui.save": "Сохранить",
-  "ui.cancel": "Отмена"
+  "ui.cancel": "Отмена",
+  "ui.deleteConfirm": "Удалить этот секрет?",
+  "ui.linkCopied": "Ссылка на секрет скопирована"
 }
diff --git a/scripts/smoke-platform-frontend.js b/scripts/smoke-platform-frontend.js
index d6ef2ff..fe17301 100644
--- a/scripts/smoke-platform-frontend.js
+++ b/scripts/smoke-platform-frontend.js
@@ -37,6 +37,15 @@ class FakeNode {
   addEventListener() {}
 }
 
+function findByClass(node, className) {
+  if (String(node.className || '').split(/\s+/).includes(className)) return node;
+  for (const child of node.children || []) {
+    const found = findByClass(child, className);
+    if (found) return found;
+  }
+  return null;
+}
+
 function makeDocument() {
   return {
     head: new FakeNode('head'),
@@ -76,6 +85,25 @@ if (!components) {
 
 const api = {
   pluginId: 'verstak.platform-test',
+  i18n: {
+    locale: 'en',
+    listeners: new Set(),
+    messages: {
+      en: { 'ui.diagnostics': 'Platform Diagnostics', 'ui.settings': 'Platform Test Settings' },
+      ru: { 'ui.diagnostics': 'Диагностика платформы', 'ui.settings': 'Настройки теста платформы' },
+    },
+    getLocale() { return this.locale; },
+    t(key, params, fallback) { return this.messages[this.locale][key] || fallback || key; },
+    onDidChangeLocale(listener) {
+      this.listeners.add(listener);
+      listener(this.locale);
+      return () => this.listeners.delete(listener);
+    },
+    setLocale(locale) {
+      this.locale = locale;
+      this.listeners.forEach((listener) => listener(locale));
+    },
+  },
   settings: {
     read: async () => 'initial value',
     write: async () => undefined,
@@ -179,9 +207,27 @@ const api = {
     if (container.children.length === 0) {
       throw new Error(`${name} mounted no DOM nodes`);
     }
+    if (name === 'DiagnosticsPanel') {
+      api.i18n.setLocale('ru');
+      if (findByClass(container, 'pt-plugin-name')?.textContent !== 'Диагностика платформы') {
+        throw new Error('DiagnosticsPanel did not update after locale change');
+      }
+    }
+    if (name === 'PlatformTestSettings') {
+      const counter = findByClass(container, 'pt-counter-value');
+      counter.textContent = '3';
+      api.i18n.setLocale('ru');
+      if (findByClass(container, 'pt-plugin-name')?.textContent !== 'Настройки теста платформы') {
+        throw new Error('PlatformTestSettings did not update after locale change');
+      }
+      if (counter.textContent !== '3') {
+        throw new Error('PlatformTestSettings lost counter state after locale change');
+      }
+    }
     if (typeof component.unmount === 'function') {
       component.unmount(container);
     }
+    api.i18n.setLocale('en');
   }
 
   console.log('platform-test frontend smoke passed');