settings trim: remove dead settings, upstream remnants, JSON/Clash subscriptions

Per SETTINGS-AUDIT (all three tiers approved 2026-10-23):

Dead settings:
- panelOutbound, ipLimitAllowlist (+ orphan parser job), outboundDownThreshold
- tg fake events outbound.down/outbound.up/xray.crash (no publisher in lite)
- phantom routing sub-tabs (Happ/Clash/Incy) and subJsonRules direct-rules tab
  (no backend keys); subHideSettings moved to the subscription info tab first

Upstream remnants:
- ldap* / smtp* model+schema keys, EmailNotifications orphan component
- twoFactorEnable/twoFactorToken + login-page probe (no backend handler)
- externalTrafficInform*

Newly approved removals:
- JSON subscription family (producer, routes, UA auto-detect, mux/finalmask/
  observatory) and Clash subscription family (producer, routes, UA detect)
- SubBalancer (table, service, controller, settings tab)
- subThemeDir (subscription page falls back to the built-in template)
- datepicker jalalian option (gregorian only; Persian picker removed)

JSON/Clash endpoints now 404; link-format output pinned by regression tests.
Guarded keys untouched: webListen/webPort/webBasePath/certs, tg* chain,
expireDiff/trafficDiff/tgBotProxy, subHideSettings, pageSize/tgLang.

frontend/src/hooks/useClients.ts

@@ -51,10 +51,6 @@ const JSON_HEADERS = { headers: { 'Content-Type': 'application/json' } } as cons
 interface SubSettings {
   enable: boolean;
   subURI: string;
-  subJsonURI: string;
-  subJsonEnable: boolean;
-  subClashURI: string;
-  subClashEnable: boolean;
   publicHost: string;
 }
 
@@ -267,22 +263,9 @@ export function useClients(options: UseClientsOptions = {}) {
     () => ({
       enable: !!defaults.subEnable,
       subURI: (defaults.subURI as string) || '',
-      subJsonURI: (defaults.subJsonURI as string) || '',
-      subJsonEnable: !!defaults.subJsonEnable,
-      subClashURI: (defaults.subClashURI as string) || '',
-      subClashEnable: !!defaults.subClashEnable,
       publicHost: (defaults.subDomain as string) || (defaults.webDomain as string) || '',
     }),
-    [
-      defaults.subEnable,
-      defaults.subURI,
-      defaults.subJsonURI,
-      defaults.subJsonEnable,
-      defaults.subClashURI,
-      defaults.subClashEnable,
-      defaults.subDomain,
-      defaults.webDomain,
-    ],
+    [defaults.subEnable, defaults.subURI, defaults.subDomain, defaults.webDomain],
   );
 
   const ipLimitEnable = !!defaults.ipLimitEnable;