fix(nests): T14 recognise Goaway control type instead of silent FIN

moq-rs's `Publisher::run` accepts `ControlType::Goaway = 5` as a
graceful-shutdown signal that asks the publisher to migrate to a
different relay node (`rs/moq-lite/src/lite/publisher.rs`). Our enum
only defined Session/Announce/Subscribe/Fetch/Probe; an inbound
Goaway bidi fell through `MoqLiteControlType.fromCode` as `null`,
hit the unknown-control branch in `handleInboundBidi`, and was FIN'd
silently — losing the relay's shutdown notification entirely.

Add `Goaway(5L)` to the enum and a dedicated arm in `handleInboundBidi`
that logs the event and FINs cleanly. We don't act on the migration
request today (no body decode, no preferred-relay failover); the
`connectReconnecting*` wrappers' transport-loss reconnect path
already recovers from the eventual hard disconnect, so all this arm
needs is to surface the relay's intent in logcat instead of
swallowing it. Wire body decoding is left as a follow-up.

https://claude.ai/code/session_014JfZJHSTvyYYWJbC9VbB47

nestsClient/src/commonMain/kotlin/com/vitorpamplona/nestsclient/moq/lite/MoqLiteMessages.kt

@@ -73,6 +73,17 @@ enum class MoqLiteControlType(
     Subscribe(2L),
     Fetch(3L),
     Probe(4L),
+
+    /**
+     * Graceful relay-shutdown signal. moq-rs's `Publisher::run` accepts
+     * `ControlType::Goaway = 5` (`rs/moq-lite/src/lite/publisher.rs`)
+     * to migrate a publisher to a different relay node. We don't act
+     * on it today — recognising the type code prevents
+     * [MoqLiteSession.handleInboundBidi] from silently FINing the
+     * bidi as an unknown control type, which would lose the relay's
+     * shutdown notification. Wire body decoding is left as a follow-up.
+     */
+    Goaway(5L),
     ;
 
     companion object {

nestsClient/src/commonMain/kotlin/com/vitorpamplona/nestsclient/moq/lite/MoqLiteSession.kt

@@ -953,6 +953,25 @@ class MoqLiteSession internal constructor(
                             runCatching { bidi.finish() }
                             dispatched = true
                         }
+
+                        MoqLiteControlType.Goaway -> {
+                            // Relay's graceful-shutdown signal — see
+                            // [MoqLiteControlType.Goaway]. We don't
+                            // act on the migration request today
+                            // (no body decode, no preferred-relay
+                            // failover); the `connectReconnecting*`
+                            // wrappers' transport-loss reconnect path
+                            // already handles the eventual hard
+                            // disconnect, so all this arm needs to do
+                            // is recognise the type code and FIN
+                            // cleanly instead of treating it as an
+                            // unknown control. Logged so a relay-
+                            // initiated migration shows up in logcat
+                            // rather than as a mystery silent reconnect.
+                            Log.w("NestRx") { "Goaway received from relay — FIN bidi (no migration handler today)" }
+                            runCatching { bidi.finish() }
+                            dispatched = true
+                        }
                     }
                 }
                 // Post-dispatch chunks are silently discarded —