fix: extract hardcoded English strings to i18n system with Russian translations

- Extract ~40 hardcoded strings from project detail, deploy, settings, credentials, registries, auth, env editor pages
- Add corresponding Russian translations
- Replace native confirm() default labels with i18n keys in ConfirmDialog
- Fix InstanceCard pluralization to use i18n

web/src/lib/components/InstanceCard.svelte

@@ -155,7 +155,7 @@
 	open={confirmAction !== null}
 	title={confirmAction ? $t(`confirm.${confirmAction}Instance`) : ''}
 	message={confirmAction ? $t(`instance.${confirmAction}Confirm`) : ''}
-	confirmLabel={confirmAction ? confirmAction.charAt(0).toUpperCase() + confirmAction.slice(1) : ''}
+	confirmLabel={confirmAction ? $t(`confirm.${confirmAction}Action`) : ''}
 	confirmVariant={confirmAction === 'remove' ? 'danger' : 'primary'}
 	onconfirm={() => { if (confirmAction) handleAction(confirmAction); }}
 	oncancel={() => { confirmAction = null; }}