refactor: make config pure, group tc fwd tables, tidy dns resolution …

…state

Fix native Windows TUN setup (#133)

* Drop malformed TUN packets

* fix: Fix Windows IPv6 alias configuration

Use the netsh ipv6 context for IPv6 address aliases instead of the IPv4 interface ip context so Windows nodes can assign their Nylon ULA address.

* fix(tun): set Windows adapter MTU

Wintun adapters can come up with a 65535 IPv6 MTU on Windows, while Nylon internally assumes the configured TUN MTU. That lets the OS hand oversized packets to the device and can trigger malformed packet handling downstream.

Set the Windows IP interface MTU from the requested TUN MTU immediately after adapter creation. IPv6 MTU setup is required because Nylon routes IPv6 overlay traffic; IPv4 is set best-effort when available.

fix(core): stabilize direct endpoint probing (#125)

Register probe tokens before sending packets so fast LAN pong replies cannot
arrive before tracking exists. Recompute routes when inbound probes revive or
create direct endpoints, keeping direct peer routes selected after recovery.

doc: add demo to docs, reword some things (#117)

doc: add asciinema demo (#112)

refactor(state): per-instance parameter tuning (#103)

fixes issues with multiple nylon instances (in tests) all sharing the same global router tuning parameters and debug flags.

fixes test case pollution across runs

fix: remove gateway when configuring routes (#49)

tweak: increase seqno when entering passive hold

fix: log path in args

feat: adjust passive keepalive to eagerly expire routes (#27)