feat(tun): expose mihomo tun dns-mode in TUN settings

Support the dns-mode field introduced in mihomo v1.19.33. A
button group below the stack selector offers
Auto/Disabled/Native/Hijack; Auto writes an empty string, which
the core treats as the legacy behavior. Adding dns-mode to
GUI_KEYS makes the value GUI-authoritative once saved, matching
the other TUN dialog fields.

src/types/generated/i18n-keys.ts

@@ -704,9 +704,11 @@ export const translationKeys = [
   'settings.modals.tun.fields.strictRoute',
   'settings.modals.tun.fields.autoDetectInterface',
   'settings.modals.tun.fields.dnsHijack',
+  'settings.modals.tun.fields.dnsMode',
   'settings.modals.tun.fields.mtu',
   'settings.modals.tun.fields.autoRedirect',
   'settings.modals.tun.tooltips.dnsHijack',
+  'settings.modals.tun.tooltips.dnsMode',
   'settings.modals.tun.tooltips.autoRedirect',
   'settings.modals.tun.messages.applied',
   'settings.modals.tun.messages.invalidRouteExcludeAddress',

src/types/generated/i18n-resources.ts

@@ -1190,6 +1190,7 @@ export interface TranslationResources {
             autoRoute: string
             device: string
             dnsHijack: string
+            dnsMode: string
             mtu: string
             routeExcludeAddress: string
             stack: string
@@ -1204,6 +1205,7 @@ export interface TranslationResources {
           tooltips: {
             autoRedirect: string
             dnsHijack: string
+            dnsMode: string
           }
         }
         update: {

src/types/global.d.ts

@@ -40,6 +40,7 @@ interface IConfigData {
     'auto-redirect'?: boolean
     'auto-detect-interface': boolean
     'dns-hijack': string[]
+    'dns-mode'?: string
     'route-exclude-address'?: string[]
     'strict-route': boolean
     mtu: number