feat: pin frequently-used tools to the top of the dashboard (#440)

* feat(i18n): add pin/unpin/pinned strings, retire addToFavourites stub

Claude-Session: https://claude.ai/code/session_01Ad5LjCDJyW1tLFd3P4Hedp

* feat(web): add per-user pinned-tools store

Claude-Session: https://claude.ai/code/session_01Ad5LjCDJyW1tLFd3P4Hedp

* feat(web): add opt-in pin toggle to ToolCard

Claude-Session: https://claude.ai/code/session_01Ad5LjCDJyW1tLFd3P4Hedp

* feat(web): render Pinned section on the dashboard All tab

Claude-Session: https://claude.ai/code/session_01Ad5LjCDJyW1tLFd3P4Hedp

* test(web): cover pin toggle (component) and dashboard pin flow (e2e)

Claude-Session: https://claude.ai/code/session_01Ad5LjCDJyW1tLFd3P4Hedp

packages/shared/src/i18n/ru.ts

@@ -2967,6 +2967,7 @@ export const ru: TranslationKeys = {
     allTools: "Все инструменты",
     searchPlaceholder: "Поиск среди {count} инструментов...",
     recent: "Недавние",
+    pinned: "Закреплённые",
     popular: "Популярные",
     browseByCategory: "По категориям",
     gettingStarted: "Начало работы",
@@ -3872,7 +3873,8 @@ export const ru: TranslationKeys = {
     settings: "Настройки",
   },
   toolCard: {
-    addToFavourites: "Добавить в избранное",
+    pin: "Закрепить",
+    unpin: "Открепить",
   },
   appLayout: {
     mobileNavTools: "Инструменты",