fix(outbounds): support proxyProtocol on freedom outbound

Xray's freedom outbound accepts a numeric proxyProtocol (0 disabled,
1 or 2 for the PROXY protocol version), but the panel had no field for
it and the typed form adapter dropped the key on save — so a value set
via the JSON editor disappeared the moment the outbound was saved.

Model proxyProtocol through the freedom wire schema, the form schema,
and both adapter directions (clamped to 0/1/2, omitted from the wire
when 0), and add a Select (none / v1 / v2) to the freedom section of
the outbound form. Add round-trip test coverage and the proxyProtocol
label across all locales.

Closes #4486

web/translation/ar-EG.json

@@ -1209,6 +1209,7 @@
         "interface": "الواجهة",
         "ipv6Only": "IPv6 فقط",
         "acceptProxyProtocol": "قبول proxy protocol",
+        "proxyProtocol": "Proxy protocol",
         "tcpUserTimeoutMs": "TCP user timeout (ms)",
         "tcpKeepAliveIdleS": "TCP keep-alive idle (ثانية)"
       },

web/translation/en-US.json

@@ -1209,6 +1209,7 @@
         "interface": "Interface",
         "ipv6Only": "IPv6 only",
         "acceptProxyProtocol": "Accept proxy protocol",
+        "proxyProtocol": "Proxy protocol",
         "tcpUserTimeoutMs": "TCP user timeout (ms)",
         "tcpKeepAliveIdleS": "TCP keep-alive idle (s)"
       },

web/translation/es-ES.json

@@ -1209,6 +1209,7 @@
         "interface": "Interfaz",
         "ipv6Only": "Solo IPv6",
         "acceptProxyProtocol": "Aceptar proxy protocol",
+        "proxyProtocol": "Proxy protocol",
         "tcpUserTimeoutMs": "TCP user timeout (ms)",
         "tcpKeepAliveIdleS": "TCP keep-alive idle (s)"
       },

web/translation/fa-IR.json

@@ -1209,6 +1209,7 @@
         "interface": "رابط",
         "ipv6Only": "فقط IPv6",
         "acceptProxyProtocol": "پذیرش Proxy Protocol",
+        "proxyProtocol": "Proxy Protocol",
         "tcpUserTimeoutMs": "TCP user timeout (ms)",
         "tcpKeepAliveIdleS": "TCP keep-alive idle (s)"
       },

web/translation/id-ID.json

@@ -1209,6 +1209,7 @@
         "interface": "Interface",
         "ipv6Only": "Hanya IPv6",
         "acceptProxyProtocol": "Terima proxy protocol",
+        "proxyProtocol": "Proxy protocol",
         "tcpUserTimeoutMs": "TCP user timeout (ms)",
         "tcpKeepAliveIdleS": "TCP keep-alive idle (d)"
       },

web/translation/ja-JP.json

@@ -1209,6 +1209,7 @@
         "interface": "インターフェース",
         "ipv6Only": "IPv6 のみ",
         "acceptProxyProtocol": "proxy protocol を受け入れる",
+        "proxyProtocol": "Proxy protocol",
         "tcpUserTimeoutMs": "TCP user timeout (ms)",
         "tcpKeepAliveIdleS": "TCP keep-alive idle (秒)"
       },

web/translation/pt-BR.json

@@ -1209,6 +1209,7 @@
         "interface": "Interface",
         "ipv6Only": "Apenas IPv6",
         "acceptProxyProtocol": "Aceitar proxy protocol",
+        "proxyProtocol": "Proxy protocol",
         "tcpUserTimeoutMs": "TCP user timeout (ms)",
         "tcpKeepAliveIdleS": "TCP keep-alive idle (s)"
       },

web/translation/ru-RU.json

@@ -1209,6 +1209,7 @@
         "interface": "Интерфейс",
         "ipv6Only": "Только IPv6",
         "acceptProxyProtocol": "Принимать proxy protocol",
+        "proxyProtocol": "Proxy protocol",
         "tcpUserTimeoutMs": "TCP user timeout (мс)",
         "tcpKeepAliveIdleS": "TCP keep-alive idle (с)"
       },

web/translation/tr-TR.json

@@ -1209,6 +1209,7 @@
         "interface": "Arabirim",
         "ipv6Only": "Yalnızca IPv6",
         "acceptProxyProtocol": "Proxy protocol kabul et",
+        "proxyProtocol": "Proxy protocol",
         "tcpUserTimeoutMs": "TCP user timeout (ms)",
         "tcpKeepAliveIdleS": "TCP keep-alive idle (s)"
       },

web/translation/uk-UA.json

@@ -1209,6 +1209,7 @@
         "interface": "Інтерфейс",
         "ipv6Only": "Лише IPv6",
         "acceptProxyProtocol": "Приймати proxy protocol",
+        "proxyProtocol": "Proxy protocol",
         "tcpUserTimeoutMs": "TCP user timeout (мс)",
         "tcpKeepAliveIdleS": "TCP keep-alive idle (с)"
       },

web/translation/vi-VN.json

@@ -1209,6 +1209,7 @@
         "interface": "Giao diện",
         "ipv6Only": "Chỉ IPv6",
         "acceptProxyProtocol": "Chấp nhận proxy protocol",
+        "proxyProtocol": "Proxy protocol",
         "tcpUserTimeoutMs": "TCP user timeout (ms)",
         "tcpKeepAliveIdleS": "TCP keep-alive idle (s)"
       },

web/translation/zh-CN.json

@@ -1209,6 +1209,7 @@
         "interface": "接口",
         "ipv6Only": "仅 IPv6",
         "acceptProxyProtocol": "接受 proxy protocol",
+        "proxyProtocol": "Proxy protocol",
         "tcpUserTimeoutMs": "TCP user timeout (ms)",
         "tcpKeepAliveIdleS": "TCP keep-alive idle (s)"
       },

web/translation/zh-TW.json

@@ -1209,6 +1209,7 @@
         "interface": "介面",
         "ipv6Only": "僅 IPv6",
         "acceptProxyProtocol": "接受 proxy protocol",
+        "proxyProtocol": "Proxy protocol",
         "tcpUserTimeoutMs": "TCP user timeout (ms)",
         "tcpKeepAliveIdleS": "TCP keep-alive idle (s)"
       },