Integrity requirements

• I have read all the comments in the issue template and ensured that this issue meet the requirements.
• I confirm that I have read the documentation, understand the meaning of all the configuration items I wrote, and did not pile up seemingly useful options or default values.
• I provided the complete config and logs, rather than just providing the truncated parts based on my own judgment.
• I searched issues and did not find any similar issues.
• The problem can be successfully reproduced in the latest Release

Description

According to #5414 (comment), session id can be placed in path, but when specifying "sessionPlacement": "path", Xray returns the error infra/conf: unsupported session placement: path

Reproduction Method

Set sessionPlacement in the config to path

Client config

{
"log": {
"loglevel": "debug"
},
"inbounds": [
{
"tag": "SOCKS",
"port": 10808,
"listen": "127.0.0.1",
"protocol": "socks",
"settings": {
"udp": true
},
"sniffing": {
"enabled": true,
"destOverride": ["http", "tls"]
}
}
],
"outbounds": [
{
"tag": "PROXY",
"protocol": "vless",
"settings": {
"address": "ip",
"port": 443,
"id": "uuid",
"encryption": "none"
},
"streamSettings": {
"network": "xhttp",
"security": "tls",
"tlsSettings": {
"alpn": ["h3"],
"serverName": "domain"
},
"xhttpSettings": {
"host": "host",
"path": "/path",
"mode": "packet-up",
"extra": {
"sessionPlacement": "path"
}
}
}
}
]
}

Server config

{
"log": {
"loglevel": "debug"
},
"inbounds": [
{
"tag": "XHTTP",
"listen": "127.0.0.1",
"port": 7777
"protocol": "vless",
"settings": {
"clients": [],
"decryption": "none"
},
"sniffing": {
"enabled": true,
"destOverride": ["http", "tls"]
},
"streamSettings": {
"network": "xhttp",
"xhttpSettings": {
"path": "/path",
"sessionPlacement": "path"
}
}
}
],
"outbounds": [
{
"tag": "DIRECT",
"protocol": "direct"
}
]
}

Client log

Xray 26.1.31 (Xray, Penetrates Everything.) 20cf00c (go1.25.6 windows/amd64)
A unified platform for anti-censorship.
Failed to start: main: failed to load config files: [config.json] > infra/conf: failed to build outbound config with tag PROXY > infra/conf: failed to build stream settings for outbound detour > infra/conf: Failed to build XHTTP config. > infra/conf: unsupported session placement: path

Server log

Xray 26.1.31 (Xray, Penetrates Everything.) 20cf00c (go1.25.6 linux/amd64)
A unified platform for anti-censorship.
Failed to start: main: failed to load config files: [config.json] > infra/conf: failed to build inbound config with tag XHTTP > infra/conf: Failed to build XHTTP config. > infra/conf: SeqPlacement must be path when SessionPlacement is path