Add NTNRC client to pAIs digital messenger (#86820)

## About The Pull Request

Just adds the NTNRC client to the pAI digital messenger software's
starting programs.
To avoid also giving this to the AI, creates a new silicon PDA subtype
for pAIs and applies it similarly to borgs.
## Why It's Good For The Game

It's already barely ever used, and I just think it'd be fun to let pAIs
talk to the never-checked department consoles or open chatrooms with
each other or their hosts.
Currently you can do this by being in your host's PDA, but this means
they couldn't use their PDA at the same time as you just... chatting.
Nor could you share a chatroom with them, due to sharing the same
account.
Also the pAI cabal using the bootleg IRC client to plot their next move
is just incredibly funny to me.
## Changelog
🆑
balance: The pAI digital messenger software now includes the NTNRC
client.
/🆑

code/modules/modular_computers/computers/item/pda.dm

@@ -322,6 +322,12 @@
 	///Ref to the silicon we're installed in. Set by the silicon itself during its creation.
 	var/mob/living/silicon/silicon_owner
 
+/obj/item/modular_computer/pda/silicon/pai
+	starting_programs = list(
+		/datum/computer_file/program/messenger,
+		/datum/computer_file/program/chatclient,
+	)
+
 /obj/item/modular_computer/pda/silicon/cyborg
 	starting_programs = list(
 		/datum/computer_file/program/filemanager,