fix: run API server in LocalSet to fix spawn_local panic

Co-authored-by: aider (gemini/gemini-2.5-pro-preview-05-06) <aider@aider.chat>

src/main.rs

@@ -18,7 +18,7 @@ use std::{
     sync::{Arc, Mutex, mpsc},
     thread,
 };
-use tokio::task;
+use tokio::task::{self, LocalSet};
 
 /// Embed the default config.json at compile time.
 const DEFAULT_CONFIG: &str = include_str!("../config.json");
@@ -77,7 +77,11 @@ async fn main() {
         });
     }
 
-    // 6️⃣ Spawn the API server thread
+    // 6️⃣ Set up a LocalSet for the API server.
+    let local = LocalSet::new();
+    local
+        .run_until(async move {
+            // 7️⃣ Spawn the API server thread
             {
                 let api_state = ltc_state.clone();
                 let offset_clone = hw_offset.clone();
@@ -88,11 +92,17 @@ async fn main() {
                 });
             }
 
-    // 7️⃣ Keep main thread alive by processing LTC frames
+            // 8️⃣ Keep main thread alive by consuming LTC frames in a blocking task
             println!("📡 Main thread entering loop...");
+            let _ = task::spawn_blocking(move || {
+                // This will block the thread, but it's a blocking-safe thread.
                 for _frame in rx {
                     // no-op
                 }
+            })
+            .await;
+        })
+        .await;
 }
 
 #[cfg(test)]