Fix WireGuard inbound domain-based routing

[Copilot]

WireGuard inbound sniffing/routing broken since PR #4030. The sniffingRequest and tag were stored in a shared routingInfo struct during Process(), causing race conditions when multiple peers connect concurrently—each call overwrites the session info used by forwardConnection().

Changes

• Store config at init time: Extract tag and sniffingRequest from context in NewServer() (same pattern as TUN handler)
• Simplify routingInfo: Remove inboundTag/contentTag fields, keep only ctx and dispatcher
• Use saved values per-connection: forwardConnection() creates fresh session.Inbound and session.Content using stored config

// Before: stored during Process(), shared across connections
s.info = routingInfo{
    inboundTag: session.InboundFromContext(ctx),
    contentTag: session.ContentFromContext(ctx),
}

// After: stored during NewServer(), immutable
if inbound := session.InboundFromContext(ctx); inbound != nil {
    server.tag = inbound.Tag
}
if content := session.ContentFromContext(ctx); content != nil {
    server.sniffingRequest = content.SniffingRequest
}

Original prompt

深刻理解 Xray-core 和依赖库的代码以及 #4760 所述的问题，自己找出真正的问题所在并修复它

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[RPRX]

#5517 (comment)

[RPRX]

感觉 4.5 opus 比 3.5 sonnet 的解决方案更好，@yuhan6665 看一下