feat: implement billboard monitor support and remove legacy code

autorun/startup.lua

@@ -28,8 +28,6 @@ elseif cfgExists('.webbridge_config') then
     role = 'bridge'
 elseif cfgExists('.miner_config') then
     role = 'miner'
-elseif cfgExists('.billboard_config') then
-    role = 'billboard'
 elseif _G.turtle then
     role = 'turtle'
 end
@@ -69,12 +67,11 @@ end
 -------------------------------------------------
 
 local programs = {
-    manager   = 'inventoryManager.lua',
-    client    = 'inventoryClient.lua',
-    bridge    = 'inventoryWebBridge.lua',
-    turtle    = 'craftingTurtle.lua',
-    miner     = 'miningTurtle.lua',
-    billboard = 'monitorBillboard.lua',
+    manager = 'inventoryManager.lua',
+    client  = 'inventoryClient.lua',
+    bridge  = 'inventoryWebBridge.lua',
+    turtle  = 'craftingTurtle.lua',
+    miner   = 'miningTurtle.lua',
 }
 
 local program = fs.combine(BASE, programs[role])