feat: Enhance turtle management by broadcasting removal notifications and cleaning up stale turtles

client/src/store/turtleStore.js

@@ -49,11 +49,21 @@ export const useTurtleStore = create((set, get) => ({
           if (data.turtle.surroundings && data.turtle.position && data.turtle.facing !== undefined) {
             get().updateBlocksFromSurroundings(data.turtle);
           }
-        } else if (data.type === 'turtle_disconnected') {
+        } else if (data.type === 'turtle_removed' || data.type === 'turtle_disconnected') {
+          console.log(`🔌 Turtle ${data.turtleID} removed`);
           set(state => {
             const newTurtles = { ...state.turtles };
             delete newTurtles[data.turtleID];
-            return { turtles: newTurtles };
+            
+            // If the removed turtle was selected, deselect it
+            const newSelectedId = state.selectedTurtleId === data.turtleID 
+              ? null 
+              : state.selectedTurtleId;
+            
+            return { 
+              turtles: newTurtles,
+              selectedTurtleId: newSelectedId
+            };
           });
         }
       } catch (error) {

server/server.js

@@ -15,6 +15,43 @@ const webClients = new Set();
 const turtleData = new Map(); // turtleID -> turtle state
 const worldBlocks = new Map(); // "x,y,z" -> {name, metadata, discoveredBy, timestamp}
 
+// Timeout for considering turtles offline (30 seconds)
+const TURTLE_TIMEOUT = 30000;
+
+// Broadcast to all web clients
+function broadcastToClients(data) {
+  const message = JSON.stringify(data);
+  webClients.forEach((client) => {
+    if (client.readyState === 1) { // OPEN
+      client.send(message);
+    }
+  });
+}
+
+// Cleanup stale turtles periodically
+setInterval(() => {
+  const now = Date.now();
+  let removedCount = 0;
+  
+  for (const [turtleID, turtle] of turtleData.entries()) {
+    if (now - turtle.lastUpdate > TURTLE_TIMEOUT) {
+      console.log(`🔌 Turtle ${turtleID} timed out (last seen ${Math.floor((now - turtle.lastUpdate) / 1000)}s ago)`);
+      turtleData.delete(turtleID);
+      removedCount++;
+      
+      // Notify web clients
+      broadcastToClients({
+        type: 'turtle_removed',
+        turtleID: turtleID
+      });
+    }
+  }
+  
+  if (removedCount > 0) {
+    console.log(`🧹 Cleaned up ${removedCount} offline turtle(s)`);
+  }
+}, 10000); // Check every 10 seconds
+
 // Helper to store discovered blocks
 function storeBlock(x, y, z, blockData, turtleID) {
   const key = `${x},${y},${z}`;
@@ -113,16 +150,6 @@ wss.on('connection', (ws) => {
   });
 });
 
-// Broadcast to all web clients
-function broadcastToClients(data) {
-  const message = JSON.stringify(data);
-  webClients.forEach((client) => {
-    if (client.readyState === 1) { // OPEN
-      client.send(message);
-    }
-  });
-}
-
 // REST API endpoint for turtles to update their status
 app.post('/api/turtle/update', (req, res) => {
   try {