refactor: replace hardcoded channel IDs with dynamic retrieval from platform.channels

pocketremote.lua

@@ -1,9 +1,12 @@
 -- Touch-Enabled Command Center for Pocket Computer (FIXED)
 -- Monitor and control autonomous mining turtles
 
-local CHANNEL_SEND = 100
-local CHANNEL_RECEIVE = 101
-local STATUS_CHANNEL = 102
+local Channels  = require('platform.channels')
+local WebBridge = require('platform.webbridge')
+
+local CHANNEL_SEND    = Channels.get('remoteturtle.command')
+local CHANNEL_RECEIVE = Channels.get('remoteturtle.response')
+local STATUS_CHANNEL  = Channels.get('remoteturtle.status')
 
 local modem = peripheral.find("modem")
 if not modem then
@@ -15,8 +18,10 @@ if pocket then
     modem = peripheral.find("modem")
 end
 
-modem.open(CHANNEL_RECEIVE)
-modem.open(STATUS_CHANNEL)
+WebBridge.openChannels(modem, {
+    'remoteturtle.response',
+    'remoteturtle.status',
+})
 
 local w, h = term.getSize()