fix(sockopt): honor trustedXForwardedFor on gRPC inbounds (xray v26.6.22) (#5503)

* fix(sockopt): honor trustedXForwardedFor on gRPC inbounds

xray-core v26.6.22 (commit 711aea4) switched the gRPC server from reading
the x-real-ip gRPC metadata to resolving the client IP from X-Forwarded-For
via sockopt.trustedXForwardedFor, matching ws/httpupgrade/xhttp.

The panel already exposed the trustedXForwardedFor field and wire output, but
the per-transport gate (TRUSTED_HEADER_NETWORKS) still omitted grpc. On a gRPC
inbound this raised a false "transport does not honor this header" warning and
mis-flagged the Cloudflare real-client-IP preset. Add grpc to the gate.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

* docs(i18n): note gRPC in trustedXForwardedFor hint (all locales)

Follow-up to the gRPC gate fix: the trustedXForwardedForHint tooltip across
all 13 locales said the header is honored "only on WebSocket, HTTPUpgrade and
XHTTP". xray-core v26.6.22 added gRPC, so list it too.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

---------

Co-authored-by: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

internal/web/translation/zh-CN.json

@@ -582,7 +582,7 @@
         "tcpCongestion": "TCP Congestion",
         "dialerProxy": "Dialer Proxy",
         "trustedXForwardedFor": "可信 X-Forwarded-For",
-        "trustedXForwardedForHint": "信任此请求头来获取真实客户端 IP（例如 Cloudflare CDN 后的 CF-Connecting-IP）。仅在 WebSocket、HTTPUpgrade 和 XHTTP 传输上生效。留空则忽略转发头。",
+        "trustedXForwardedForHint": "信任此请求头来获取真实客户端 IP（例如 Cloudflare CDN 后的 CF-Connecting-IP）。仅在 WebSocket、HTTPUpgrade、XHTTP 和 gRPC 传输上生效。留空则忽略转发头。",
         "proxyProtocolHint": "接受 PROXY protocol 头，从上游 L4 隧道或中继（HAProxy、gost、nginx-stream、Xray dokodemo-door）或 Cloudflare Spectrum 获取真实客户端 IP。上游必须发送 PROXY protocol。适用于 TCP、WebSocket、HTTPUpgrade 和 gRPC；不适用于 mKCP。",
         "realClientIp": "真实客户端 IP",
         "realClientIpHint": "当流量通过 CDN 或中继到达此入站时，获取访客的真实 IP，而不是记录中间节点的地址。选择一个预设以自动填写下方对应的 sockopt 字段。这些字段绝不会在订阅中发送给客户端。",