feat(sub): let the panel set the JSON subscription DNS servers (#6485)

* feat(sub): let the panel set the JSON subscription DNS servers

A baked routing profile (#6402) carries only the DNS its preset defines, so an
operator who wants their own resolvers has to override the whole profile or
patch the subscription behind a proxy.

Add the subJsonDns setting: either a full xray dns block or a bare array of
servers. It wins over the profile's DNS while leaving the profile's routing
rules intact, and reaches per-inbound, balancer and info-node documents alike.

The value is validated with xray's own schema (internal/xray/dnsconf): a block
the client could not load is rejected when the settings are saved and ignored
with a warning at request time, instead of being baked into every document.
Both the sub server and the settings API share that validator, so a stored
value can never be silently dropped.

xray's Build() is deliberately not used for validation: it resolves geosite
tokens from the geodata files and would reject valid configs whenever those
are absent from the panel's working directory.

* style(dnsconf): drop the ineffectual initial map assignment

golangci's ineffassign flagged the zero-value map whose value both paths
overwrite: the object branch now assigns the decoded map directly.

* docs(sub): scope the DNS setting to the documents it rewrites

The Routing header mirrored to Happ/INCY keeps the routing profile's own
resolvers, so the setting description and the header-source comment now say
so instead of claiming the profile's DNS is replaced everywhere.

Also trims two comments in the new dnsconf package to the repo's two-line cap.

frontend/src/generated/examples.ts

@@ -88,6 +88,7 @@ export const EXAMPLES: Record<string, unknown> = {
     "subInfoNodeEnable": false,
     "subJsonAlwaysArray": false,
     "subJsonAutoDetect": false,
+    "subJsonDns": "",
     "subJsonEnable": false,
     "subJsonFinalMask": "",
     "subJsonMux": "",
@@ -229,6 +230,7 @@ export const EXAMPLES: Record<string, unknown> = {
     "subInfoNodeEnable": false,
     "subJsonAlwaysArray": false,
     "subJsonAutoDetect": false,
+    "subJsonDns": "",
     "subJsonEnable": false,
     "subJsonFinalMask": "",
     "subJsonMux": "",

frontend/src/generated/schemas.ts

@@ -282,6 +282,9 @@ export const SCHEMAS: Record<string, unknown> = {
       "subJsonAutoDetect": {
         "type": "boolean"
       },
+      "subJsonDns": {
+        "type": "string"
+      },
       "subJsonEnable": {
         "type": "boolean"
       },
@@ -519,6 +522,7 @@ export const SCHEMAS: Record<string, unknown> = {
       "subInfoNodeEnable",
       "subJsonAlwaysArray",
       "subJsonAutoDetect",
+      "subJsonDns",
       "subJsonEnable",
       "subJsonFinalMask",
       "subJsonMux",
@@ -870,6 +874,9 @@ export const SCHEMAS: Record<string, unknown> = {
       "subJsonAutoDetect": {
         "type": "boolean"
       },
+      "subJsonDns": {
+        "type": "string"
+      },
       "subJsonEnable": {
         "type": "boolean"
       },
@@ -1114,6 +1121,7 @@ export const SCHEMAS: Record<string, unknown> = {
       "subInfoNodeEnable",
       "subJsonAlwaysArray",
       "subJsonAutoDetect",
+      "subJsonDns",
       "subJsonEnable",
       "subJsonFinalMask",
       "subJsonMux",

frontend/src/generated/types.ts

@@ -96,6 +96,7 @@ export interface AllSetting {
   subInfoNodeEnable: boolean;
   subJsonAlwaysArray: boolean;
   subJsonAutoDetect: boolean;
+  subJsonDns: string;
   subJsonEnable: boolean;
   subJsonFinalMask: string;
   subJsonMux: string;
@@ -238,6 +239,7 @@ export interface AllSettingView {
   subInfoNodeEnable: boolean;
   subJsonAlwaysArray: boolean;
   subJsonAutoDetect: boolean;
+  subJsonDns: string;
   subJsonEnable: boolean;
   subJsonFinalMask: string;
   subJsonMux: string;

frontend/src/generated/zod.ts

@@ -112,6 +112,7 @@ export const AllSettingSchema = z.object({
   subInfoNodeEnable: z.boolean(),
   subJsonAlwaysArray: z.boolean(),
   subJsonAutoDetect: z.boolean(),
+  subJsonDns: z.string(),
   subJsonEnable: z.boolean(),
   subJsonFinalMask: z.string(),
   subJsonMux: z.string(),
@@ -255,6 +256,7 @@ export const AllSettingViewSchema = z.object({
   subInfoNodeEnable: z.boolean(),
   subJsonAlwaysArray: z.boolean(),
   subJsonAutoDetect: z.boolean(),
+  subJsonDns: z.string(),
   subJsonEnable: z.boolean(),
   subJsonFinalMask: z.string(),
   subJsonMux: z.string(),

frontend/src/models/setting.ts

@@ -70,6 +70,7 @@ export class AllSetting {
   subJsonMux = '';
   subJsonRules = '';
   subJsonRoutingRules = '';
+  subJsonDns = '';
   subJsonFinalMask = '';
   subJsonObservatory = '';
   subThemeDir = '';

frontend/src/pages/settings/SubscriptionFormatsTab.tsx

@@ -241,6 +241,18 @@ export default function SubscriptionFormatsTab({
                       autoSize={{ minRows: 2, maxRows: 6 }}
                     />
                   </SettingListItem>
+                  <SettingListItem
+                    paddings="small"
+                    title={t('pages.settings.subJsonDns')}
+                    description={t('pages.settings.subJsonDnsDesc')}
+                  >
+                    <Input.TextArea
+                      value={allSetting.subJsonDns}
+                      placeholder='{"servers": ["https://dns.google/dns-query", "tls://1.1.1.1"]}'
+                      onChange={(e) => updateSetting({ subJsonDns: e.target.value })}
+                      autoSize={{ minRows: 2, maxRows: 6 }}
+                    />
+                  </SettingListItem>
                 </Card>
               )}
               {allSetting.subClashEnable && (

frontend/src/schemas/setting.ts

@@ -75,6 +75,7 @@ export const AllSettingSchema = z
     subJsonMux: z.string().optional(),
     subJsonRules: z.string().optional(),
     subJsonRoutingRules: z.string().optional(),
+    subJsonDns: z.string().optional(),
     subJsonFinalMask: z.string().optional(),
     subJsonObservatory: z.string().optional(),
     subHideSettings: z.boolean().optional(),