qdisc: expose traffic shaping info via netcfg and LinkDevice trait

LinkDevice gains qdisc_info() → String defaulting to 'none'.
EthernetLink reports current qdisc configuration:
  none  /  token_bucket rate=N burst=N tokens=N  /  priority_queue len=N max=N

TokenBucket and PriorityQueue gain public accessor methods:
  rate(), burst(), tokens() / max_len()

netcfg exposes at /scheme/netcfg/ifaces/eth0/qdisc:
  cat /scheme/netcfg/ifaces/eth0/qdisc  →  'none' (default)

Enables monitoring tools to discover current traffic shaping.
Future: wo node for configuring qdisc type + parameters.

netstack/src/link/ethernet.rs

@@ -882,5 +882,17 @@ impl LinkDevice for EthernetLink {
     fn link_state(&self) -> &'static str {
         if self.hardware_address.is_some() { "up" } else { "down" }
     }
+
+    fn qdisc_info(&self) -> String {
+        match &self.qdisc_config {
+            QdiscConfig::None => "none\n".to_string(),
+            QdiscConfig::TokenBucket(tb) => {
+                format!("token_bucket rate={} burst={} tokens={}\n", tb.rate(), tb.burst(), tb.tokens())
+            }
+            QdiscConfig::PriorityQueue(pq) => {
+                format!("priority_queue len={} max={}\n", pq.len(), pq.max_len())
+            }
+        }
+    }
 }
 

netstack/src/link/mod.rs

@@ -49,6 +49,10 @@ pub trait LinkDevice {
         String::new()
     }
 
+    fn qdisc_info(&self) -> String {
+        "none\n".to_string()
+    }
+
     fn mtu(&self) -> usize {
         1500
     }

netstack/src/link/qdisc.rs

@@ -25,13 +25,11 @@ pub struct TokenBucket {
 
 impl TokenBucket {
     pub fn new(rate_bps: u64, burst_bytes: u64) -> Self {
-        Self {
-            rate: rate_bps,
-            burst: burst_bytes.max(1500),
-            tokens: burst_bytes.max(1500),
-            last_update: Instant::from_millis(0),
-        }
+        Self { rate: rate_bps, burst: burst_bytes.max(1500), tokens: burst_bytes.max(1500), last_update: Instant::from_millis(0) }
     }
+    pub fn rate(&self) -> u64 { self.rate }
+    pub fn burst(&self) -> u64 { self.burst }
+    pub fn tokens(&self) -> u64 { self.tokens }
 
     pub fn set_rate(&mut self, rate_bps: u64) {
         self.rate = rate_bps;
@@ -67,12 +65,8 @@ pub struct PriorityQueue {
 }
 
 impl PriorityQueue {
-    pub fn new(max_len: usize) -> Self {
-        Self {
-            bands: [VecDeque::new(), VecDeque::new(), VecDeque::new()],
-            max_len,
-        }
-    }
+    pub fn new(max_len: usize) -> Self { Self { bands: [VecDeque::new(), VecDeque::new(), VecDeque::new()], max_len } }
+    pub fn max_len(&self) -> usize { self.max_len }
 
     fn classify(packet: &[u8]) -> usize {
         if packet.len() < 2 || packet[0] >> 4 != 4 {

netstack/src/scheme/netcfg/mod.rs

@@ -458,6 +458,14 @@ fn mk_root_node(
                             None => "Device not found\n".into(),
                         }
                     }
+                },
+                "qdisc" => {
+                    ro [devices] || {
+                        match devices.borrow().get("eth0") {
+                            Some(dev) => dev.qdisc_info(),
+                            None => "Device not found\n".into(),
+                        }
+                    }
                 }
             },
             "lo" => {