fix: prevent direct traffic leaks during profile transitions

[4RH1T3CT0R7]

The existing profile switch path stops the current core before starting the next one. Closing the core also removes the TUN adapter, routes, DNS handling, and sing-tun's dynamic WFP filters. During that gap, Windows can use the physical default route again.

This adds an opt-in Windows kill switch in Tun Settings. It installs fail-closed Windows Filtering Platform policy before any profile is torn down and keeps direct traffic blocked while Throne is connecting, switching, reconnecting, disconnected, or in an error state. The setting is disabled by default.

Implementation

• Adds persistent IPv4 and IPv6 block filters at the ALE connect and receive/accept layers.
• Uses dynamic allowances for ThroneCore bootstrap traffic and for the active TUN interface only.
• Removes the TUN allowance before stopping or restarting the core.
• Keeps the persistent block after manual disconnect, failed start, normal exit, and unexpected GUI/core termination.
• Reconciles stale Throne-owned policy at startup and modifies only objects carrying Throne's deterministic ownership markers.
• Adds an explicit --disable-kill-switch recovery path and runs it during uninstall.
• Constrains endpoint bootstrap DNS to an encrypted resolver with a numeric IPv4 or IPv6 address.
• Forces ordinary DNS and routing through the proxy while the kill switch is active.
• Rejects profiles and routing modes whose direct behavior cannot be safely audited, including opaque full configs, ExtraCore, direct/SOCKS4/Tailscale profiles, auto-selector, and immutable raw routes.
• Blocks LAN access in the first version, apart from loopback and narrowly scoped DHCP/IPv6 control traffic.

Fixes #1611

[Mahdi-zarei]

These changes are too intrusive and hard to maintain, i need more time to review and see if such a feature as you have proposed is feasible to have.

[4RH1T3CT0R7]

These changes are too intrusive and hard to maintain, i need more time to review and see if such a feature as you have proposed is feasible to have.

I can break this down into several logical parts if this will help

[Mahdi-zarei]

I can break this down into several logical parts if this will help

No not really, I will try to get back to you as soon as i can.