feat: add full Russian language support; update Readme.md files, and .gitignore update (#514)

* feat: add Russian locale

- Add ru translations and register namespaces

- Add Russian to supported languages list

- Ignore .gemini workspace config

* fix: improve Russian plural forms in sidebar translations

Add proper Russian plural forms (few/many) for correct grammar with different count values

* docs(readme): add Russian translation and fix language switcher order

- Create README.ru.md based on the current English README.
- Update language switchers in all localized README files so
    English comes first, Russian second, and the remaining
    languages follow.
- Fix the issue where the current language was not shown
    correctly in the switcher for some localized README files

* fix(readme): fix language switcher positions and markdown issues

- Fix language switcher positions in README.md.
- Add bash language tags to command code blocks in README.ru.md.

* fix(readme): fix tool setup step numbering

- Fix tool setup step numbering in README.md and localized README files.

* fix(gitignore): allow translation task files to be tracked

Add exceptions to .gitignore for task translation files across multiple locales
(en, ja, ru, ko, zh-CN) to enable version control of translated content while
keeping generated task files ignored.

Co-Authored-By: Claude Haiku 4.5 <noreply@anthropic.com>

* feat(i18n): add Russian translation for tasks

Add Russian locale translation file for TaskMaster task management interface.

Co-Authored-By: Claude Haiku 4.5 <noreply@anthropic.com>

* fix: ignore missing tasks.json files for ko and zh-cn locales

* Delete .worktrees directory

---------

Co-authored-by: Claude Haiku 4.5 <noreply@anthropic.com>

src/i18n/locales/ru/auth.json

@@ -0,0 +1,37 @@
+{
+  "login": {
+    "title": "Добро пожаловать",
+    "description": "Войдите в свой аккаунт Claude Code UI",
+    "username": "Имя пользователя",
+    "password": "Пароль",
+    "submit": "Войти",
+    "loading": "Вход...",
+    "errors": {
+      "invalidCredentials": "Неверное имя пользователя или пароль",
+      "requiredFields": "Пожалуйста, заполните все поля",
+      "networkError": "Ошибка сети. Попробуйте снова."
+    },
+    "placeholders": {
+      "username": "Введите имя пользователя",
+      "password": "Введите пароль"
+    }
+  },
+  "register": {
+    "title": "Создать аккаунт",
+    "username": "Имя пользователя",
+    "password": "Пароль",
+    "confirmPassword": "Подтвердите пароль",
+    "submit": "Создать аккаунт",
+    "loading": "Создание аккаунта...",
+    "errors": {
+      "passwordMismatch": "Пароли не совпадают",
+      "usernameTaken": "Имя пользователя уже занято",
+      "weakPassword": "Пароль слишком слабый"
+    }
+  },
+  "logout": {
+    "title": "Выйти",
+    "confirm": "Вы уверены, что хотите выйти?",
+    "button": "Выйти"
+  }
+}