fix: derive wifi interface dynamically from gateway info instead of detecting at startup

Remove static wifi_interface/ethernet_interface fields from RpcContextSeed. Instead, look up
the wifi interface from the DB (populated by gateway sync) and check ethernet connectivity
by querying gateway entries. This ensures the wifi manager always uses the correct interface
even if network devices change after boot.

core/src/context/rpc.rs

@@ -35,7 +35,6 @@ use crate::lxc::LxcManager;
 use crate::net::gateway::WildcardListener;
 use crate::net::net_controller::{NetController, NetService};
 use crate::net::socks::DEFAULT_SOCKS_LISTEN;
-use crate::net::utils::{find_eth_iface, find_wifi_iface};
 use crate::net::web_server::WebServerAcceptorSetter;
 use crate::net::wifi::WpaCli;
 use crate::prelude::*;
@@ -55,8 +54,6 @@ use crate::{DATA_DIR, PLATFORM, PackageId};
 pub struct RpcContextSeed {
     is_closed: AtomicBool,
     pub os_partitions: OsPartitionInfo,
-    pub wifi_interface: Option<String>,
-    pub ethernet_interface: String,
     pub disk_guid: InternedString,
     pub ephemeral_sessions: SyncMutex<Sessions>,
     pub db: TypedPatchDb<Database>,
@@ -73,7 +70,7 @@ pub struct RpcContextSeed {
     pub open_authed_continuations: OpenAuthedContinuations<Option<InternedString>>,
     pub rpc_continuations: RpcContinuations,
     pub callbacks: Arc<ServiceCallbacks>,
-    pub wifi_manager: Arc<RwLock<Option<WpaCli>>>,
+    pub wifi_manager: RwLock<Option<WpaCli>>,
     pub current_secret: Arc<Jwk>,
     pub client: Client,
     pub start_time: Instant,
@@ -323,13 +320,9 @@ impl RpcContext {
             });
         }
 
-        let wifi_interface = find_wifi_iface().await?;
-
         let seed = Arc::new(RpcContextSeed {
             is_closed: AtomicBool::new(false),
             os_partitions: OsPartitionInfo::from_fstab().await?,
-            wifi_interface: wifi_interface.clone(),
-            ethernet_interface: find_eth_iface().await?,
             disk_guid,
             ephemeral_sessions: SyncMutex::new(Sessions::new()),
             sync_db: watch::Sender::new(db.sequence().await),
@@ -350,7 +343,7 @@ impl RpcContext {
             shutdown,
             lxc_manager: Arc::new(LxcManager::new()),
             open_authed_continuations: OpenAuthedContinuations::new(),
-            wifi_manager: Arc::new(RwLock::new(wifi_interface.clone().map(|i| WpaCli::init(i)))),
+            wifi_manager: RwLock::new(None),
             current_secret: Arc::new(
                 Jwk::generate_ec_key(josekit::jwk::alg::ec::EcCurve::P256).map_err(|e| {
                     tracing::debug!("{:?}", e);