feat(lint): Add rule to validate i18next usage

[andreaskienle]

This PR adds eslint-plugin-i18next to automatically detect missing i18next translations.

A lot of changes to the eslint.config.js file but most of them are just the prettier (see commits).

[Copilot]

Pull Request Overview

This PR adds eslint-plugin-i18next to detect missing internationalization translations and ensures existing hardcoded strings are properly translated. The main purpose is to enforce i18n best practices and prevent untranslated text from being displayed to users.

• Adds eslint-plugin-i18next dependency and configuration to enforce i18n usage
• Replaces hardcoded strings with translated versions using the t() function
• Adds ESLint disable comments for legitimate literal strings (like shell command syntax)

Reviewed Changes

Copilot reviewed 8 out of 9 changed files in this pull request and generated no comments.

Show a summary per file

File	Description
eslint.config.js	Adds i18next plugin configuration and converts quotes from double to single
package.json	Adds eslint-plugin-i18next dependency
public/locales/en.json	Adds translation keys for newly internationalized strings
src/components/Core/ShellBar.tsx	Replaces "Beta" hardcoded text with translation
src/components/Core/IntelligentBreadcrumbs.tsx	Replaces "Projects", "Workspaces", "MCPs" with translations
src/components/ControlPlanes/CopyKubeconfigButton.tsx	Replaces "Kubeconfig" with translation
src/components/Dialogs/KubectlCommandInfo/KubectlBaseDialog.tsx	Replaces "Close" with translation
src/components/Dialogs/KubectlCommandInfo/KubectlTerminal.tsx	Adds ESLint disable comments for shell command literals

Comments suppressed due to low confidence (4)

src/components/Core/ShellBar.tsx:50

• The addition of useTranslation hook introduces new behavior that should be covered by tests to ensure the translation key 'ShellBar.betaButton' is properly resolved.

  const { t } = useTranslation();

src/components/Core/IntelligentBreadcrumbs.tsx:33

• The translation changes for breadcrumb items lack test coverage to verify that the correct translation keys are used and properly rendered.

            <BreadcrumbsItem href={`${PREFIX}/projects`}>{t('IntelligentBreadcrumbs.projects')}</BreadcrumbsItem>

src/components/ControlPlanes/CopyKubeconfigButton.tsx:29

• The replacement of hardcoded 'Kubeconfig' text with translation should be tested to ensure the translation key resolves correctly.

        {t('CopyKubeconfigButton.kubeconfigButton')}

src/components/Dialogs/KubectlCommandInfo/KubectlBaseDialog.tsx:87

• The change from hardcoded 'Close' to translation key 'common.close' should be tested to verify proper translation rendering in the dialog footer.

      footer={<Bar endContent={<Button onClick={onClose}>{t('common.close')}</Button>} />}