feat(plugins): sandboxed page/widget frames + trekBridge (M3)

Plugins can now render UI. Page plugins appear as a nav entry and open a
full-page sandboxed iframe; the frame talks to TREK only over the postMessage
bridge.

- Server serves plugin client assets at /plugin-frame/:id/* with a strict path
  guard and a locked-down, per-plugin CSP (default-src none; connect-src limited
  to declared outbound hosts; sandbox WITHOUT allow-same-origin -> opaque origin,
  so the frame can't read the session cookie or the parent DOM). Global CSP
  frameSrc relaxed from 'none' to 'self' for exactly these frames.
- GET /api/plugins feed lists active plugins for the client.
- Client: pluginStore + PluginFrame (the trekBridge host) authenticates every
  inbound message by SENDER WINDOW IDENTITY (event.source), not by a claimed id
  or origin; pushes context (theme/locale/tripId/userId), validates navigation,
  renders notifications as text, resizes widgets, and proxies trek:invoke to the
  plugin's own routes host-side (session cookie stays with the host).
- Page route /plugins/:id + Navbar nav injection for page plugins.

Dashboard widget slot and the trek:request core-data bridge are deferred to a
later slice.

shared/src/i18n/ar/admin.ts

@@ -178,6 +178,7 @@ const admin: TranslationStrings = {
   'admin.packingTemplates.saveError': 'فشل الحفظ',
   'admin.tabs.addons': 'الإضافات',
   'admin.tabs.plugins': 'Plugins',
+  'plugins.notFound': 'Plugin not found',
   'admin.plugins.title': 'Plugins',
   'admin.plugins.subtitle': 'Install and manage third-party plugins on your instance.',
   'admin.plugins.disabledTitle': 'Plugins are disabled',

shared/src/i18n/br/admin.ts

@@ -157,6 +157,7 @@ const admin: TranslationStrings = {
   'admin.packingTemplates.saveError': 'Falha ao salvar',
   'admin.tabs.addons': 'Complementos',
   'admin.tabs.plugins': 'Plugins',
+  'plugins.notFound': 'Plugin not found',
   'admin.plugins.title': 'Plugins',
   'admin.plugins.subtitle': 'Install and manage third-party plugins on your instance.',
   'admin.plugins.disabledTitle': 'Plugins are disabled',

shared/src/i18n/cs/admin.ts

@@ -158,6 +158,7 @@ const admin: TranslationStrings = {
   'admin.packingTemplates.saveError': 'Uložení se nezdařilo',
   'admin.tabs.addons': 'Doplňky',
   'admin.tabs.plugins': 'Plugins',
+  'plugins.notFound': 'Plugin not found',
   'admin.plugins.title': 'Plugins',
   'admin.plugins.subtitle': 'Install and manage third-party plugins on your instance.',
   'admin.plugins.disabledTitle': 'Plugins are disabled',

shared/src/i18n/de/admin.ts

@@ -160,6 +160,7 @@ const admin: TranslationStrings = {
   'admin.packingTemplates.saveError': 'Fehler beim Speichern',
   'admin.tabs.addons': 'Addons',
   'admin.tabs.plugins': 'Plugins',
+  'plugins.notFound': 'Plugin nicht gefunden',
   'admin.plugins.title': 'Plugins',
   'admin.plugins.subtitle': 'Plugins von Drittanbietern auf deiner Instanz installieren und verwalten.',
   'admin.plugins.disabledTitle': 'Plugins sind deaktiviert',

shared/src/i18n/en/admin.ts

@@ -212,6 +212,7 @@ const admin: TranslationStrings = {
   'admin.packingTemplates.saveError': 'Failed to save',
   'admin.tabs.addons': 'Addons',
   'admin.tabs.plugins': 'Plugins',
+  'plugins.notFound': 'Plugin not found',
   'admin.plugins.title': 'Plugins',
   'admin.plugins.subtitle': 'Install and manage third-party plugins on your instance.',
   'admin.plugins.disabledTitle': 'Plugins are disabled',

shared/src/i18n/es/admin.ts

@@ -159,6 +159,7 @@ const admin: TranslationStrings = {
   'admin.packingTemplates.saveError': 'Error al guardar',
   'admin.tabs.addons': 'Complementos',
   'admin.tabs.plugins': 'Plugins',
+  'plugins.notFound': 'Plugin not found',
   'admin.plugins.title': 'Plugins',
   'admin.plugins.subtitle': 'Install and manage third-party plugins on your instance.',
   'admin.plugins.disabledTitle': 'Plugins are disabled',

shared/src/i18n/fr/admin.ts

@@ -161,6 +161,7 @@ const admin: TranslationStrings = {
   'admin.packingTemplates.saveError': 'Erreur de sauvegarde',
   'admin.tabs.addons': 'Extensions',
   'admin.tabs.plugins': 'Plugins',
+  'plugins.notFound': 'Plugin not found',
   'admin.plugins.title': 'Plugins',
   'admin.plugins.subtitle': 'Install and manage third-party plugins on your instance.',
   'admin.plugins.disabledTitle': 'Plugins are disabled',

shared/src/i18n/gr/admin.ts

@@ -206,6 +206,7 @@ const admin: TranslationStrings = {
   'admin.packingTemplates.saveError': 'Αποτυχία αποθήκευσης',
   'admin.tabs.addons': 'Πρόσθετα',
   'admin.tabs.plugins': 'Plugins',
+  'plugins.notFound': 'Plugin not found',
   'admin.plugins.title': 'Plugins',
   'admin.plugins.subtitle': 'Install and manage third-party plugins on your instance.',
   'admin.plugins.disabledTitle': 'Plugins are disabled',

shared/src/i18n/hu/admin.ts

@@ -160,6 +160,7 @@ const admin: TranslationStrings = {
   'admin.packingTemplates.saveError': 'Nem sikerült menteni',
   'admin.tabs.addons': 'Bővítmények',
   'admin.tabs.plugins': 'Plugins',
+  'plugins.notFound': 'Plugin not found',
   'admin.plugins.title': 'Plugins',
   'admin.plugins.subtitle': 'Install and manage third-party plugins on your instance.',
   'admin.plugins.disabledTitle': 'Plugins are disabled',

shared/src/i18n/id/admin.ts

@@ -202,6 +202,7 @@ const admin: TranslationStrings = {
   'admin.packingTemplates.saveError': 'Gagal menyimpan',
   'admin.tabs.addons': 'Addon',
   'admin.tabs.plugins': 'Plugins',
+  'plugins.notFound': 'Plugin not found',
   'admin.plugins.title': 'Plugins',
   'admin.plugins.subtitle': 'Install and manage third-party plugins on your instance.',
   'admin.plugins.disabledTitle': 'Plugins are disabled',

shared/src/i18n/it/admin.ts

@@ -159,6 +159,7 @@ const admin: TranslationStrings = {
   'admin.packingTemplates.saveError': 'Impossibile salvare',
   'admin.tabs.addons': 'Moduli',
   'admin.tabs.plugins': 'Plugins',
+  'plugins.notFound': 'Plugin not found',
   'admin.plugins.title': 'Plugins',
   'admin.plugins.subtitle': 'Install and manage third-party plugins on your instance.',
   'admin.plugins.disabledTitle': 'Plugins are disabled',

shared/src/i18n/ja/admin.ts

@@ -191,6 +191,7 @@ const admin: TranslationStrings = {
   'admin.packingTemplates.saveError': '保存に失敗しました',
   'admin.tabs.addons': 'アドオン',
   'admin.tabs.plugins': 'Plugins',
+  'plugins.notFound': 'Plugin not found',
   'admin.plugins.title': 'Plugins',
   'admin.plugins.subtitle': 'Install and manage third-party plugins on your instance.',
   'admin.plugins.disabledTitle': 'Plugins are disabled',

shared/src/i18n/ko/admin.ts

@@ -197,6 +197,7 @@ const admin: TranslationStrings = {
   'admin.packingTemplates.saveError': '저장 실패',
   'admin.tabs.addons': '애드온',
   'admin.tabs.plugins': 'Plugins',
+  'plugins.notFound': 'Plugin not found',
   'admin.plugins.title': 'Plugins',
   'admin.plugins.subtitle': 'Install and manage third-party plugins on your instance.',
   'admin.plugins.disabledTitle': 'Plugins are disabled',

shared/src/i18n/nl/admin.ts

@@ -160,6 +160,7 @@ const admin: TranslationStrings = {
   'admin.packingTemplates.saveError': 'Fout bij opslaan',
   'admin.tabs.addons': 'Add-ons',
   'admin.tabs.plugins': 'Plugins',
+  'plugins.notFound': 'Plugin not found',
   'admin.plugins.title': 'Plugins',
   'admin.plugins.subtitle': 'Install and manage third-party plugins on your instance.',
   'admin.plugins.disabledTitle': 'Plugins are disabled',

shared/src/i18n/pl/admin.ts

@@ -153,6 +153,7 @@ const admin: TranslationStrings = {
   'admin.packingTemplates.saveError': 'Nie udało się zapisać szablonu',
   'admin.tabs.addons': 'Dodatki',
   'admin.tabs.plugins': 'Plugins',
+  'plugins.notFound': 'Plugin not found',
   'admin.plugins.title': 'Plugins',
   'admin.plugins.subtitle': 'Install and manage third-party plugins on your instance.',
   'admin.plugins.disabledTitle': 'Plugins are disabled',

shared/src/i18n/ru/admin.ts

@@ -160,6 +160,7 @@ const admin: TranslationStrings = {
   'admin.packingTemplates.saveError': 'Ошибка сохранения',
   'admin.tabs.addons': 'Дополнения',
   'admin.tabs.plugins': 'Plugins',
+  'plugins.notFound': 'Plugin not found',
   'admin.plugins.title': 'Plugins',
   'admin.plugins.subtitle': 'Install and manage third-party plugins on your instance.',
   'admin.plugins.disabledTitle': 'Plugins are disabled',

shared/src/i18n/sv/admin.ts

@@ -212,6 +212,7 @@ const admin: TranslationStrings = {
   'admin.packingTemplates.saveError': 'Det gick inte att spara',
   'admin.tabs.addons': 'Tillägg',
   'admin.tabs.plugins': 'Plugins',
+  'plugins.notFound': 'Plugin not found',
   'admin.plugins.title': 'Plugins',
   'admin.plugins.subtitle': 'Install and manage third-party plugins on your instance.',
   'admin.plugins.disabledTitle': 'Plugins are disabled',

shared/src/i18n/tr/admin.ts

@@ -204,6 +204,7 @@ const admin: TranslationStrings = {
   'admin.packingTemplates.saveError': 'Kaydedilemedi',
   'admin.tabs.addons': 'Eklentiler',
   'admin.tabs.plugins': 'Plugins',
+  'plugins.notFound': 'Plugin not found',
   'admin.plugins.title': 'Plugins',
   'admin.plugins.subtitle': 'Install and manage third-party plugins on your instance.',
   'admin.plugins.disabledTitle': 'Plugins are disabled',

shared/src/i18n/uk/admin.ts

@@ -160,6 +160,7 @@ const admin: TranslationStrings = {
   'admin.packingTemplates.saveError': 'Помилка збереження',
   'admin.tabs.addons': 'Дополнения',
   'admin.tabs.plugins': 'Plugins',
+  'plugins.notFound': 'Plugin not found',
   'admin.plugins.title': 'Plugins',
   'admin.plugins.subtitle': 'Install and manage third-party plugins on your instance.',
   'admin.plugins.disabledTitle': 'Plugins are disabled',

shared/src/i18n/vi/admin.ts

@@ -212,6 +212,7 @@ const admin: TranslationStrings = {
   'admin.packingTemplates.saveError': 'Không lưu được',
   'admin.tabs.addons': 'Tiện ích bổ sung',
   'admin.tabs.plugins': 'Plugins',
+  'plugins.notFound': 'Plugin not found',
   'admin.plugins.title': 'Plugins',
   'admin.plugins.subtitle': 'Install and manage third-party plugins on your instance.',
   'admin.plugins.disabledTitle': 'Plugins are disabled',

shared/src/i18n/zh-TW/admin.ts

@@ -194,6 +194,7 @@ const admin: TranslationStrings = {
   'admin.packingTemplates.saveError': '儲存失敗',
   'admin.tabs.addons': '擴充套件',
   'admin.tabs.plugins': 'Plugins',
+  'plugins.notFound': 'Plugin not found',
   'admin.plugins.title': 'Plugins',
   'admin.plugins.subtitle': 'Install and manage third-party plugins on your instance.',
   'admin.plugins.disabledTitle': 'Plugins are disabled',

shared/src/i18n/zh/admin.ts

@@ -155,6 +155,7 @@ const admin: TranslationStrings = {
   'admin.packingTemplates.saveError': '保存失败',
   'admin.tabs.addons': '扩展',
   'admin.tabs.plugins': 'Plugins',
+  'plugins.notFound': 'Plugin not found',
   'admin.plugins.title': 'Plugins',
   'admin.plugins.subtitle': 'Install and manage third-party plugins on your instance.',
   'admin.plugins.disabledTitle': 'Plugins are disabled',