control: add iroh gossip transport announcements and ec-node control CLI

crates/ec-core/src/lib.rs

@@ -183,6 +183,32 @@ pub struct StreamCatalog {
     pub entries: Vec<StreamCatalogEntry>,
 }
 
+#[derive(Debug, Clone, Serialize, Deserialize)]
+#[serde(tag = "kind", rename_all = "snake_case")]
+pub enum StreamTransportDescriptor {
+    /// Stream is available via a MoQ relay over WebTransport/WebSocket.
+    RelayMoq {
+        url: String,
+        broadcast_name: String,
+        track_name: String,
+    },
+    /// Stream is available via iroh direct MoQ.
+    IrohDirect {
+        endpoint: String,
+        broadcast_name: String,
+        track_name: String,
+    },
+}
+
+#[derive(Debug, Clone, Serialize, Deserialize)]
+pub struct StreamControlAnnouncement {
+    pub stream: StreamDescriptor,
+    pub transports: Vec<StreamTransportDescriptor>,
+    pub updated_unix_ms: u64,
+    /// Suggested freshness window for this announcement.
+    pub ttl_ms: u64,
+}
+
 #[derive(Debug, Clone, Serialize, Deserialize)]
 pub struct ManifestSummary {
     pub manifest_id: String,