The Windows TAP pump used the same send helper as direct callers, so malformed,
jumbo, or over-budget TAP frames were reported as errors that stopped the
bridge. That is too brittle for the no-fragmentation MVP: local frames that
cannot fit the tunnel should be counted and dropped, while real QUIC send
failures should still surface as fatal.
Add a client send outcome that reports whether a frame was sent or locally
dropped. The existing send_ethernet API still returns an error for direct
callers when the outcome is a local drop. The live TAP pump uses the outcome API
so it can log the drop reason and keep forwarding later frames.
Document the new client behavior in the README.
Test Plan:
- cargo fmt --check
- git diff --check
- cargo test -p lanparty-client-core
- cargo test -p lanparty-client-win
- cargo test --workspace
- cargo clippy --workspace --all-targets -- -D warnings
Attempted:
- cargo check -p lanparty-client-win --target x86_64-pc-windows-msvc
(blocked by missing MSVC lib.exe on this Linux host)
Refs: PLAN.md
The PLAN calls out client diagnostics that a user can read directly, not only
machine-shaped counters. The Windows client already built ClientDiagnostics
snapshots, but it printed a dense status line and left the UserDiagnostic model
unused.
Derive user-facing diagnostics from ClientDiagnostics in lanparty-obs so a
future GUI and the current CLI can share the same status vocabulary. The
messages report the states the runtime actually observes: relay reachability,
LAN gateway presence, TAP IP presence, and observed broadcast traffic. TAP IPs
are only described as DHCP when they are non-link-local IPv4 addresses, because
link-local IPv4 and IPv6 addresses do not prove DHCP success.
The client now prints those user-facing lines after the existing detailed
counter line. Gateway latency is intentionally not reported here; the current
protocol does not measure gateway RTT.
Test Plan:
- cargo fmt --check
- cargo test -p lanparty-obs -p lanparty-client-win
- cargo test --workspace
- cargo clippy --workspace --all-targets -- -D warnings
- git diff --check
- git diff --cached --check
Refs: PLAN.md Logging / diagnostics
PLAN.md calls for a user-facing warning when TAP routing could steal the
relay path. The client already disables TAP default routes under a scoped guard,
but the startup output only reported the previous raw flag value.
Format the route-protection message as a warning whenever default routes were
enabled before the scoped override. Keep the already-disabled case quiet and
explicit, and cover both messages with tests that run on non-Windows builds.
Document the startup warning alongside the existing route-protection behavior.
Test Plan:
- cargo fmt --check
- cargo test -p lanparty-client-win -p lanparty-client-route
- cargo test --workspace
- cargo clippy --workspace --all-targets -- -D warnings
- git diff --check
Refs: PLAN.md
PLAN.md calls out "Broadcast traffic flowing" as a user-facing diagnostic.
The tunnel stats only reported total Ethernet frame counts, so the client
could not distinguish whether broadcast traffic was actually crossing the
tunnel.
Add defaulted broadcast tx/rx counters to TunnelStats while preserving the
existing constructor and old JSON compatibility. Client and gateway accounting
now increments those counters from validated Ethernet frames, and the client
diagnostics line reports the broadcast flow next to total frame counts.
Relay peer stats logs include the new counters so operators can see broadcast
activity from forwarded stats snapshots too.
Test Plan:
- cargo fmt --check
- cargo test -p lanparty-obs -p lanparty-client-core -p lanparty-gateway \
-p lanparty-client-win -p lanparty-relay
- cargo test --workspace
- cargo clippy --workspace --all-targets -- -D warnings
- git diff --check
Refs: PLAN.md
PLAN.md calls for user-facing diagnostics that can say whether the remote
client is connected to the LAN gateway. Startup already reported the initial
welcome bit, but periodic diagnostics only carried relay reachability and route
pinning.
Add gateway_connected to RelayDiagnostics and seed the client status from the
welcome. The client control-event logger now updates that status when gateway
join and leave events arrive, so later diagnostics reflect relay lifecycle
changes while the tunnel is running.
Test Plan:
- cargo fmt --check
- cargo test -p lanparty-obs -p lanparty-client-win
- cargo test --workspace
- cargo clippy --workspace --all-targets -- -D warnings
- git diff --check
Refs: PLAN.md
PLAN.md calls out room modes such as relay, direct-p2p, and relay fallback so
future transport choices can fit the protocol. Add an explicit ConnectionMode
field to ServerWelcome and default it to relay for existing decoded welcomes.
The relay still operates only in relay mode today. Client and gateway startup
logs now print the selected mode, which makes the current relay path visible
without changing routing or forwarding behavior.
Test Plan:
- cargo fmt --check
- cargo test -p lanparty-ctrl server_welcome -- --nocapture
- cargo test -p lanparty-client-win -p lanparty-gateway
- cargo test --workspace
- cargo clippy --workspace --all-targets -- -D warnings
- git diff --check
Refs: PLAN.md
PLAN.md describes the first client flow as entering a relay domain and room
code, but the client and gateway CLIs only accepted socket-address literals.
Add a small shared RelayEndpoint parser so bare hosts default to UDP/443 while
IP literals and explicit host:port values stay supported.
The runtime configs still store resolved SocketAddr values. That keeps the
Windows route-pinning path on a concrete relay IP before TAP activation while
avoiding duplicated endpoint grammar between client and gateway. The relay
listen config reuses the same default port constant so UDP/443 has one source.
README examples now use lanparty-relay.local and document the shared endpoint
syntax.
Test Plan:
- cargo fmt --check
- cargo test -p lanparty-net
- cargo test -p lanparty-client-win \
accepts_relay_domain_with_default_port -- --nocapture
- cargo test -p lanparty-gateway \
accepts_iface_alias_for_gateway_interface -- --nocapture
- cargo test -p lanparty-net -p lanparty-client-win -p lanparty-gateway
- cargo clippy -p lanparty-net -p lanparty-client-win -p lanparty-gateway \
--all-targets -- -D warnings
- cargo test --workspace
- cargo clippy --workspace --all-targets -- -D warnings
- git diff --check
Refs: PLAN.md
The Windows client sampled TAP diagnostics once when opening the adapter. That
can miss the useful DHCP result because the TAP interface may not receive a LAN
address until after frame bridging starts.
Keep the stable TAP diagnostics fields from startup, but retain the interface
identity and re-read the TAP unicast IP whenever the periodic diagnostics tick
prints and reports a snapshot. Later status lines can now show the DHCP address
that arrives after the tunnel is already moving traffic.
Test Plan:
- cargo fmt --check
- cargo test -p lanparty-client-win
- cargo test --workspace
- cargo clippy --workspace --all-targets -- -D warnings
- git diff --check
Refs: PLAN.md
The Windows client already generates and announces a stable locally administered
MAC, but it only rejected the TAP adapter when the driver reported a different
address. Persist the tunnel MAC to tap-windows6's NetworkAddress registry value
before opening the adapter so the driver can load the intended current address.
The TAP crate now keeps the driver registry key name from discovery, formats the
NetworkAddress value as the 12-digit hex string expected by NDIS, and rejects
invalid multicast, broadcast, or globally administered MACs before writing.
Runtime validation stays in place. tap-windows6 reads NetworkAddress during
adapter initialization, so an adapter that Windows already initialized with an
old value may still need disable/enable or reinstall on the real Windows test
machine before the GET_MAC ioctl reports the new identity.
Test Plan:
- cargo fmt --check
- cargo test -p lanparty-client-tap
- cargo test -p lanparty-client-win
- cargo clippy -p lanparty-client-tap --all-targets -- -D warnings
- cargo check -p lanparty-client-tap --target x86_64-pc-windows-gnu
- cargo check -p lanparty-client-tap --target x86_64-pc-windows-msvc
- cargo test --workspace
- cargo clippy --workspace --all-targets -- -D warnings
- git diff --check
Refs: PLAN.md
Client counters were only local diagnostics even though the control protocol and
relay now understand Stats messages. Add a client-core sender that opens a
peer-to-relay unidirectional stream with the current TunnelStats snapshot.
The Windows client reports stats whenever it prints its diagnostics snapshot.
Failures are logged instead of stopping the frame pump because stats reporting
is diagnostic and should not be the reason a live tunnel goes down.
The client-core integration test now has the server decode the stats stream
before shutdown so the send path is covered without a timing race.
Test Plan:
- cargo fmt --check
- cargo test -p lanparty-client-core \
connects_to_relay_control_stream_as_client -- --nocapture
- cargo test -p lanparty-client-core
- cargo test -p lanparty-client-win
- cargo clippy -p lanparty-client-core --all-targets -- -D warnings
- cargo clippy -p lanparty-client-win --all-targets -- -D warnings
- cargo test --workspace
- cargo clippy --workspace --all-targets -- -D warnings
- git diff --check
Refs: PLAN.md
The relay now sends enough PeerJoined events for the client to learn the peers
already in the room, but the client was still formatting PeerLeft with only the
bare peer id. That made a gateway disconnect look the same as any other peer
leaving.
Keep a small in-memory peer map in the control-event logger. PeerJoined records
or refreshes the peer identity, and PeerLeft removes it before formatting the
message. Unknown leaves still use the generic fallback, so out-of-order or
missed events remain understandable.
Test Plan:
- cargo fmt --check
- cargo test -p lanparty-client-win formats_relay_lifecycle_events \
-- --nocapture
- cargo test -p lanparty-client-win
- cargo clippy -p lanparty-client-win --all-targets -- -D warnings
- cargo test --workspace
- cargo clippy --workspace --all-targets -- -D warnings
- git diff --check
Refs: PLAN.md
The Windows client now listens for relay control events while the TAP frame pump
is running and logs peer lifecycle updates as they arrive. Gateway joins get a
clear LAN-gateway message, client joins include their virtual MAC, and peer
leaves include the relay-provided reason.
The non-Windows placeholder path also listens for the same events while waiting
for Ctrl-C. That keeps lifecycle diagnostics visible in local relay/client smoke
tests even before the Windows TAP path can be exercised on a real machine.
Test Plan:
- cargo fmt --check
- cargo test -p lanparty-client-win
- cargo clippy -p lanparty-client-win --all-targets -- -D warnings
- cargo test --workspace
- cargo clippy --workspace --all-targets -- -D warnings
- git diff --check
Refs: PLAN.md
ServerWelcome now carries an initial gateway_connected flag with serde defaulting
for older welcome payloads. The relay sets it from room admission state so a
gateway sees itself as connected, clients joining behind an existing gateway see
yes, and clients that arrive first see no.
The Windows client prints that handshake fact at startup. This does not replace
the later peer-event stream; it gives phase-1 diagnostics an immediate answer
for whether the relay already has a LAN gateway in the room.
Test Plan:
- cargo fmt --check
- cargo test -p lanparty-ctrl -p lanparty-relay -p lanparty-client-core \
-p lanparty-client-win
- cargo clippy -p lanparty-ctrl -p lanparty-relay -p lanparty-client-core \
-p lanparty-client-win --all-targets -- -D warnings
- cargo test --workspace
- cargo clippy --workspace --all-targets -- -D warnings
- git diff --check
Refs: PLAN.md
Add InterfaceUnicastAddress snapshots to client-route, backed by the Windows
unicast IP address table. The Windows client samples the TAP interface after it
resolves the adapter identity, preferring IPv4 for diagnostics and falling back
to the first address or unknown on lookup failure.
This keeps Win32 IP table handling in the route crate and fills the existing
TapDiagnostics IP field without making bridging depend on DHCP being present.
If DHCP has not assigned an address yet, diagnostics still make that visible as
unknown.
Test Plan:
- cargo fmt --check
- cargo test -p lanparty-client-route
- cargo test -p lanparty-client-win
- cargo check -p lanparty-client-route --target x86_64-pc-windows-gnu
- cargo check -p lanparty-client-route --target x86_64-pc-windows-gnu --tests
- cargo test --workspace
- cargo clippy --workspace --all-targets -- -D warnings
- git diff --check
Attempted:
- cargo check -p lanparty-client-route -p lanparty-client-win
--target x86_64-pc-windows-gnu
Blocked because ring needs missing x86_64-w64-mingw32-gcc here.
Refs: PLAN.md
The client now builds ClientDiagnostics snapshots from the connected session,
known TAP state, route-pinning status, and tunnel counters. Windows prints one
snapshot after TAP and relay-route setup, then repeats snapshots while bridging
so frame/datagram counters and drops are visible during manual phase-1 tests.
Non-Windows builds print the same relay and QUIC diagnostics with TAP fields
marked unknown before waiting for Ctrl-C. TAP IP remains unknown until a later
Windows adapter IP inspection slice wires that source of truth.
Test Plan:
- cargo fmt --check
- cargo test -p lanparty-client-win
- cargo clippy -p lanparty-client-win --all-targets -- -D warnings
- cargo test --workspace
- cargo clippy --workspace --all-targets -- -D warnings
- git diff --check
Refs: PLAN.md
The Windows client now sets the TAP IP-interface MTU to the relay-selected MTU
before it starts bridging frames. The override is scoped like the existing
metric and default-route guards, so the previous MTU is restored when the
client exits.
The route crate now exposes `InterfaceMtuSnapshot` and `ScopedInterfaceMtu`
around `MIB_IPINTERFACE_ROW.NlMtu`, reusing the same `GetIpInterfaceEntry` and
`SetIpInterfaceEntry` path already used for metrics and default-route policy.
IPv4 MTU setup is required for startup, while IPv6 MTU setup is best-effort to
match the existing IPv6 route-protection behavior.
This intentionally leaves TAP MAC configuration as fail-fast. TAP-Windows6 does
not expose a matching set-MAC IOCTL in the driver header, so that should remain
a separate design decision.
Test Plan:
- cargo fmt --check
- cargo test -p lanparty-client-route
- cargo test -p lanparty-client-win
- cargo clippy -p lanparty-client-route -p lanparty-client-win --all-targets
-- -D warnings
- cargo check -p lanparty-client-route --target x86_64-pc-windows-gnu
- cargo test --workspace
- cargo clippy --workspace --all-targets -- -D warnings
- git diff --check
- cargo check -p lanparty-client-win --target x86_64-pc-windows-gnu
(fails before this crate in ring: missing x86_64-w64-mingw32-gcc)
Refs: PLAN.md
The Windows client now verifies that the relay path still uses the pinned host
route after the TAP adapter is activated, and keeps checking that invariant
while frames are being bridged. If Windows starts choosing a different prefix,
next hop, or interface for the relay IP, the client exits instead of silently
letting the tunnel route itself through the TAP side.
This closes the remaining detection half of the route-protection startup flow
from PLAN.md. The previous commits installed the pre-TAP host route, scoped TAP
metrics, and disabled TAP default routes; this commit proves those protections
are still winning after TAP activation and catches later DHCP-driven route
changes during the session.
The route crate now exposes small helpers for route-interface identity and host
route matching so the client does not duplicate route-prefix semantics inline.
The full Windows client target check still cannot complete on this Linux host:
`ring` fails while compiling for `x86_64-pc-windows-msvc` because the Windows C
header `assert.h` is unavailable, before `lanparty-client-win` is typechecked.
The independent Windows-target route crate checks do pass.
Test Plan:
- cargo fmt --check
- cargo test --workspace
- cargo clippy --workspace --all-targets -- -D warnings
- cargo check -p lanparty-client-route --target x86_64-pc-windows-msvc
- cargo clippy -p lanparty-client-route --target x86_64-pc-windows-msvc --all-targets -- -D warnings
- git diff --check
Refs: PLAN.md
The Windows client now validates the driver-reported TAP MAC and MTU before it
marks the adapter media connected or starts bridging frames. If the TAP driver
settings do not match the tunnel identity and relay-selected MTU, startup fails
with a direct error instead of continuing into a session that would drop frames
or advertise the wrong L2 identity.
This is intentionally a correctness guard, not automatic configuration yet.
Until TAP MAC and MTU configuration are wired, the safe behavior is to fail
before traffic can flow. Route protection is still applied before validation and
restored if validation fails during startup.
The full Windows client target check still cannot complete on this Linux host:
`ring` fails while compiling for `x86_64-pc-windows-msvc` because the Windows C
header `assert.h` is unavailable, before `lanparty-client-win` is typechecked.
Test Plan:
- cargo fmt --check
- cargo test -p lanparty-client-win
- cargo clippy -p lanparty-client-win --all-targets -- -D warnings
- cargo test --workspace
- cargo clippy --workspace --all-targets -- -D warnings
- git diff --check
Refs: PLAN.md
The Windows client now holds scoped default-route suppression guards for the
TAP interface while the frame pump is active. IPv4 protection is required,
matching the relay-route safety path. IPv6 protection is still best-effort so
IPv4-only Windows TAP setups do not fail startup just because there is no IPv6
interface row to update.
This completes the current client-side route-policy wiring from PLAN.md: the
relay host route is pinned before TAP activation, TAP interface metrics are
raised while running, and TAP default routes are disabled until the client
exits or startup unwinds. Automatic TAP MAC and MTU configuration remain
follow-up work.
The full Windows client target check still cannot complete on this Linux host:
`ring` fails while compiling for `x86_64-pc-windows-msvc` because the Windows C
header `assert.h` is unavailable, before `lanparty-client-win` is typechecked.
The independent Windows-target route crate checks do pass.
Test Plan:
- cargo fmt --check
- cargo test --workspace
- cargo clippy --workspace --all-targets -- -D warnings
- cargo check -p lanparty-client-route --target x86_64-pc-windows-msvc
- cargo clippy -p lanparty-client-route --target x86_64-pc-windows-msvc --all-targets -- -D warnings
- git diff --check
Refs: PLAN.md
The Windows client now applies a high manual metric to the TAP interface
while the adapter is active. This keeps ordinary host routes preferred over
TAP routes during the tunnel lifetime, and the route crate guard restores the
previous metric and automatic-metric state when the client exits or startup
unwinds.
IPv4 metric protection is required because the tunnel depends on keeping the
relay path reachable. IPv6 metric protection is attempted as a best-effort
step so IPv4-only Windows setups can still run while dual-stack hosts receive
similar protection when the IPv6 interface row exists.
The metric guard is held for the same lifetime as the TAP frame pump. The
relay host-route pin remains held through QUIC shutdown. Default-route
takeover detection and automatic TAP MAC/MTU configuration are still follow-up
work from PLAN.md.
Test Plan:
- cargo fmt --check
- cargo test --workspace
- cargo clippy --workspace --all-targets -- -D warnings
- cargo check -p lanparty-client-route --target x86_64-pc-windows-msvc
- cargo clippy -p lanparty-client-route --target x86_64-pc-windows-msvc --all-targets -- -D warnings
- git diff --check
Refs: PLAN.md
Resolve the opened TAP adapter's NetCfgInstanceId to its Windows interface
index and LUID during startup, then print those values with the existing TAP
MAC/MTU diagnostics. This makes the interface identity visible before the next
metric-setting slice uses it for route protection.
The lookup failure is treated as startup failure because an opened TAP adapter
that cannot be resolved as a Windows network interface is not a good candidate
for metric or route management.
Verification note: I attempted to check `lanparty-client-win` for
`x86_64-pc-windows-msvc`, but this host still lacks the Windows C headers
needed by `ring`; the build stops at `assert.h` before the binary crate can be
typechecked for Windows.
Test Plan:
- cargo fmt --check
- cargo test --workspace
- cargo clippy --workspace --all-targets -- -D warnings
- cargo check -p lanparty-client-route --target x86_64-pc-windows-msvc
- cargo clippy -p lanparty-client-route --target x86_64-pc-windows-msvc --all-targets -- -D warnings
- git diff --check
Refs: PLAN.md
Create the relay host-route pin in the Windows client before the TAP adapter is
opened and marked connected. The guard is held until after `ClientSession`
shutdown so both the active tunnel and the QUIC close path keep using the
pre-TAP interface.
Route inspection or route creation failure now aborts startup before TAP
activation, and the client explicitly closes the relay session in that failure
path. Once the pin is installed, the client reports both the original best-route
snapshot and the pinned route. Default-route takeover detection/neutralization
is still future work.
Verification note: I attempted to check `lanparty-client-win` for
`x86_64-pc-windows-msvc`, but this host still lacks the Windows C headers
needed by `ring`; the build stops at `assert.h` before the binary crate can be
typechecked for Windows.
Test Plan:
- cargo fmt --check
- cargo test --workspace
- cargo clippy --workspace --all-targets -- -D warnings
- cargo check -p lanparty-client-route --target x86_64-pc-windows-msvc
- cargo clippy -p lanparty-client-route --target x86_64-pc-windows-msvc --all-targets -- -D warnings
- git diff --check
Refs: PLAN.md
Use the new route snapshot helper in the Windows client startup path before the
TAP adapter is opened and marked connected. The client now reports the current
relay destination route: selected source address, next hop, interface index,
interface LUID, route prefix, and metric.
This is still diagnostic only. Route pinning remains unwired, and route lookup
failure is a warning so manual TAP frame-pump testing is not blocked by a route
inspection failure. Once mutation is implemented, this snapshot gives the code
the pre-TAP interface data it needs to preserve the real internet path.
Verification note: I attempted to check `lanparty-client-win` for
`x86_64-pc-windows-msvc`, but this host still lacks the Windows C headers
needed by `ring`; the build stops at `assert.h` before the binary crate can be
typechecked for Windows.
Test Plan:
- cargo fmt --check
- cargo test --workspace
- cargo clippy --workspace --all-targets -- -D warnings
- cargo check -p lanparty-client-route --target x86_64-pc-windows-msvc
- cargo clippy -p lanparty-client-route --target x86_64-pc-windows-msvc -- -D warnings
- git diff --check
Refs: PLAN.md
Wire the Windows client run loop to move Ethernet frames between the relay
session and the opened TAP-Windows6 adapter. TAP reads use a named OS thread
because the current adapter API performs blocking synchronous reads; relay to
TAP writes use short `spawn_blocking` jobs so the async receive loop does not
block the Tokio worker.
The main function now always closes the relay session after the client run loop
finishes, including TAP pump errors. Ctrl-C still stops the client. The TAP
reader thread is intentionally detached in this first pump slice because a
blocking TAP read cannot yet be cancelled cleanly from the async side; process
exit tears it down after shutdown.
This still leaves route pinning and automatic TAP MAC/MTU configuration for
later. The README now reflects that frame pumping is wired while those Windows
network-configuration pieces remain outstanding.
Verification note: I attempted to check `lanparty-client-win` for
`x86_64-pc-windows-msvc`, but this Linux host still lacks the Windows C
headers needed by `ring`; the build stops at `assert.h` before the binary crate
can be typechecked for Windows.
Test Plan:
- cargo fmt --check
- cargo test --workspace
- cargo clippy --workspace --all-targets -- -D warnings
- CC_x86_64_pc_windows_msvc=clang-cl AR_x86_64_pc_windows_msvc=llvm-lib \
CARGO_TARGET_X86_64_PC_WINDOWS_MSVC_LINKER=lld-link cargo clippy \
-p lanparty-client-tap --target x86_64-pc-windows-msvc -- -D warnings
- git diff --check
Refs: PLAN.md
The client can now reach the relay with a stable virtual MAC, and the TAP crate
can discover and open installed TAP-Windows6 adapters. Wire those pieces
together at startup so the Windows binary opens the first TAP adapter and marks
its media status connected after the relay handshake succeeds.
The binary reports the TAP device path plus the driver MAC and MTU. If those do
not match the tunnel identity or relay-selected MTU, it warns explicitly instead
of pretending configuration is complete.
Frame pumping and route protection remain separate follow-up slices. The full
Windows client binary still cannot be target-checked on this Linux host because
its QUIC/TLS stack needs Windows C headers for ring, but the TAP crate itself is
Windows-target checked and clippy-clean.
Test Plan:
- cargo fmt --check
- cargo test --workspace
- cargo clippy --workspace --all-targets -- -D warnings
- Windows-target cargo clippy for lanparty-client-tap with -D warnings
- git diff --check
Refs: PLAN.md Windows TAP client
Remote clients need a stable locally administered MAC address so the relay,
gateway, DHCP lease, and LAN peers keep seeing the same tunnel identity across
runs. Requiring users to pass `--virtual-mac` made that responsibility manual.
Add a platform-neutral client identity store that loads a JSON identity file or
generates a new valid virtual MAC with OS randomness and persists it. The file
stores the MAC in the same string form shown by the CLI. The Windows client now
uses `lanparty-client-identity.json` by default while keeping `--virtual-mac` as
a manual test override.
TAP binding still remains future work; this slice only owns the client identity
that will be assigned to the TAP adapter.
Test Plan:
- cargo fmt --check
- cargo test --workspace
- cargo clippy --workspace --all-targets -- -D warnings
- git diff --check
Refs: PLAN.md MAC identity
lanparty-client-win now has a real command-line surface for the relay-facing
client session. It accepts the relay address, expected TLS server name, pinned
DER relay certificate, room code, virtual TAP MAC, and advertised datagram
budget, then connects through lanparty-client-core as role = client.
The binary reports the assigned peer id, room id, and effective TAP MTU from the
welcome response, then waits for Ctrl-C. TAP adapter binding and Windows route
pinning remain future slices, but the executable now exercises the real relay
control-plane path instead of the starter placeholder.
Test Plan:
- cargo fmt --check
- cargo test --workspace
- cargo clippy --workspace --all-targets -- -D warnings
Refs: PLAN.md Windows client relay connection