Add LAN sharing toggle for the local proxy port

[PhoenixNil]

Summary

• Adds an "allow LAN connections" toggle to the edit-local-port dialog. When on, the local socks/http inbound listens on 0.0.0.0 instead of 127.0.0.1, so other devices on the LAN can point their proxy settings at this machine — the same idea as v2rayN's LAN sharing.
• The dialog shows the resulting ip:port and lets you copy it (reuses the existing CopyButton control). LAN address detection reuses TunService's existing adapter-selection helpers (IsTunLikeInterface, HasIPv4Gateway) rather than re-deriving NIC selection logic.
• The port/LAN change reapplies live via the existing ReapplyRoutingAsync mechanism when xray is already running, matching how routing-mode and DNS changes already behave (no-op under TUN mode — takes effect on the next connect there).

Notes for reviewers

• No authentication is added on the inbound. This was explicitly scoped out for this pass. Enabling LAN sharing exposes an unauthenticated socks/http proxy to the local network — anyone on the same subnet can use it. Worth a deliberate decision on whether auth should land before this ships broadly.
• Windows Firewall may prompt to allow xray.exe through on first LAN-bound listen; no explicit firewall-rule handling was added, relying on the standard OS prompt.

Test plan

• dotnet build succeeds (via BuildAndRun.ps1 -SkipRun)
• Manually toggled LAN sharing on/off in the edit-port dialog, verified the address line and copy button
• Verify from a second LAN device that the proxy is reachable when enabled, and unreachable when disabled

[chatgpt-codex-connector]

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[chatgpt-codex-connector]

Avoid binding LAN sharing to every interface

When Allow LAN is enabled on a host where Windows Firewall allows xray.exe and the machine also has a VPN/public adapter, 0.0.0.0 publishes the no-auth inbound on those interfaces as well, not just the LAN address shown in the dialog. That lets peers outside the intended local subnet use the proxy. Please bind a separate LAN inbound to the selected local address while keeping loopback for local use, or make the all-interface exposure explicit.

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