Initial boilerplate scaffold for continuum-proxy

src/discovery/mod.rs

@@ -0,0 +1,44 @@
+use std::time::Duration;
+
+use serde::{Deserialize, Serialize};
+use tracing::{debug, info};
+
+#[derive(Debug, Clone, Serialize, Deserialize)]
+pub enum PrinterVendor {
+    Bambu,
+    Prusa,
+    Klipper,
+}
+
+#[derive(Debug, Clone, Serialize, Deserialize)]
+pub struct DiscoveredPrinter {
+    pub vendor: PrinterVendor,
+    pub host: String,
+    pub serial: Option<String>,
+}
+
+/// Periodically sweeps the LAN for printers (SSDP for Bambu, mDNS for
+/// PrusaLink/Moonraker) and reports newly-seen devices upstream.
+///
+/// This is intentionally a stub: production discovery would bind a UDP
+/// multicast socket per protocol. It's structured so each protocol's probe
+/// can be dropped in independently without touching the polling loop.
+pub async fn run(interval: Duration, tx: tokio::sync::mpsc::Sender<DiscoveredPrinter>) {
+    let mut ticker = tokio::time::interval(interval);
+    loop {
+        ticker.tick().await;
+        debug!("running LAN discovery sweep");
+
+        for printer in sweep().await {
+            info!(host = %printer.host, ?printer.vendor, "discovered printer");
+            if tx.send(printer).await.is_err() {
+                return;
+            }
+        }
+    }
+}
+
+async fn sweep() -> Vec<DiscoveredPrinter> {
+    // TODO: SSDP probe (Bambu), mDNS `_prusalink._tcp` / `_moonraker._tcp` probes.
+    Vec::new()
+}