fix(sub): bind JSON local inbounds to 127.0.0.1 and keep mux.cool off Vision outbounds (#6418)

* fix(sub): bind JSON local inbounds to 127.0.0.1 and keep mux.cool off Vision outbounds

The JSON subscription's local SOCKS/HTTP inbounds had no listen address, so
every client that runs the profile verbatim bound an unauthenticated proxy on
0.0.0.0, and iOS packet-tunnel clients could not reach it at all (Happ iOS:
CONNECTED with zero traffic, same symptom as #6379 — on the same device the
mixed inbound also worked once bound to 127.0.0.1). Bind both to loopback,
which is what every client's own generated config does.

The global subJsonMux was also applied to VLESS outbounds carrying
xtls-rprx-vision. XTLS flows do not support mux.cool: Xray answers the mux
handshake with "common/mux: unexpected network TCP" and the tunnel passes
nothing, on every platform (verified with Happ iOS/Android/macOS, V2Box iOS
and desktop Xray 26.6.27 against a 3x-ui 3.7.0 box with per-client traffic
counters). Skip the mux block whenever the outbound carries a flow.

Refs #6379

* fix(sub): keep XUDP settings when disabling TCP mux on Vision outbounds

Clearing the whole mux object also dropped xudpConcurrency, xudpProxyUDP443
and any per-host muxParams override. Xray reads those only under
mux.enabled, so set concurrency to -1 instead: TCP mux.cool (which XTLS flows
reject) is off, XUDP and the UDP/443 policy stay. The test now decodes each
outbound into a fresh map.

---------

Co-authored-by: Farhan Zare <[email protected]>

docs/content/docs/fa/config/subscription.mdx

@@ -58,7 +58,7 @@ https://<sub-host>:<sub-port>/<sub-path>/<sub-id>
 بدنه‌ی **Base64** صرفاً همان لینک‌های اشتراک‌گذاری است که با خط جدید به هم پیوسته و
 با standard-base64 رمزگذاری شده‌اند (با `subEncrypt` قابل تغییر است). بدنه‌ی **JSON**
 هر کلاینت را در یک پیکربندی کامل کلاینت Xray می‌پیچد — یک اسکلت ثابت (ورودی‌های محلی
-SOCKS/HTTP، DNS، مسیریابی، policy) به‌علاوه‌ی یک outbound از نوع `proxy` که به ورودی
+SOCKS/HTTP روی 127.0.0.1، DNS، مسیریابی، policy) به‌علاوه‌ی یک outbound از نوع `proxy` که به ورودی
 اشاره می‌کند. 3x-ui **برای یک کلاینت یک شیء پیکربندی واحد و برای چند کلاینت یک آرایه**
 تولید می‌کند، از فرم تخت `settings` در outbound استفاده می‌کند
 (`address`/`port`/`id`، `level: 8`) و `sockopt` را از `streamSettings` حذف می‌کند.