Restore nest filter for server discovery

WHAT WAS DONE:
- Re-added MINECRAFT_NEST_IDS filtering
- Keeps the node ID mapping fix (2→NC1, 3→TX1)

WHY:
Non-Minecraft servers were appearing in the matrix.
We need to filter to only show Minecraft servers.

Signed-off-by: Claude (Chronicler #60) <claude@firefrostgaming.com>

services/arbiter-3.0/src/panel/discovery.js

@@ -16,13 +16,18 @@ async function getMinecraftServers() {
     
     const data = await res.json();
     
+    // Parse the allowed nest IDs from the environment variable
+    const allowedNests = process.env.MINECRAFT_NEST_IDS.split(',').map(id => parseInt(id.trim(), 10));
+
     // Node ID to friendly name mapping
     const nodeMap = {
       2: 'NC1',
       3: 'TX1'
     };
 
-    return data.data.map(server => ({
+    return data.data.filter(server => {
+      return allowedNests.includes(server.attributes.nest);
+    }).map(server => ({
       identifier: server.attributes.identifier,
       name: server.attributes.name,
       nodeId: server.attributes.node,