feat(sub): opt-in dns and sniffer from remote Clash rules (#6868)

Public Mihomo templates ship rules, rule-providers and proxy-groups together
with a dns block those rules depend on (fake-ip ranges, nameserver policy).
Pasting a template inline keeps its dns, but pointing the global routing rules
at its URL dropped it, so URL users had to give up auto-refresh to keep it.

A new switch, subClashRemoteDNS (off by default), also takes the remote dns and
sniffer maps. It is opt-in because a remote dns block decides where clients send
every lookup. A malformed dns or sniffer value is skipped, not the whole template.
The component-test teardown now outlasts AntD Form's 10ms error debounce, which
otherwise fired after jsdom was gone.

frontend/src/generated/examples.ts

@@ -65,6 +65,7 @@ export const EXAMPLES: Record<string, unknown> = {
     "subClashEnable": false,
     "subClashEnableRouting": false,
     "subClashPath": "",
+    "subClashRemoteDNS": false,
     "subClashRules": "",
     "subClashURI": "",
     "subClashUserAgentRegex": "",
@@ -252,6 +253,7 @@ export const EXAMPLES: Record<string, unknown> = {
     "subClashEnable": false,
     "subClashEnableRouting": false,
     "subClashPath": "",
+    "subClashRemoteDNS": false,
     "subClashRules": "",
     "subClashURI": "",
     "subClashUserAgentRegex": "",