NTNet Extensibility (#22908)

Fixes https://github.com/Aurorastation/Aurora.3/issues/21944

Spiritual successor of
https://github.com/Aurorastation/Aurora.3/pull/22352
Cherrypicked changes from the C3 Crew Management branch, this PR
contains all NTNet extensibility features, including Field Relay
construction, off-site camera usage (contingent on standing up remote
hardware and being out of jamming), etc. This also fixes a handful of
outstanding telecomms and view/mobeye-related bugs adjacent to where I
was working.

changes:
- rscadd: "Adds NTNet extensibility, requires new machinery constructed
on away-site z-levels."
- rscadd: "Breaks NTNet Relay machinery into Quantum Relay ('core' obj
on Horizon) and Field Relay (deployable off-site constructions)."
- qol: "Embedded cameras (basically every video camera EXCEPT those
which are installed on walls) can now be viewed from NTNet-connected
z-level, not just connected ones."
- rscadd: "Adds several public camera monitor consoles to the Horizon
(near where public sensor grid feed consoles already exist)."
- rscadd: "Adds some spare camera console boards to Horizon technical
storage."
- qol: "Adds action button for 'cancel-camera-view' verb while viewing
cameras or looking up/down z-level."
- bugfix: "Fixes Jockey comms (frequency was missing from ANTAG_FREQS)."
- bugfix: "Fixes look-up/look-down actions intermittently failing
without first using cancel-camera-view."

code/modules/overmap/sectors.dm

@@ -112,6 +112,10 @@ GLOBAL_DATUM(map_overmap, /area/overmap)
 	for(var/obj/structure/machinery/telecomms/T in SSmachinery.all_telecomms)
 		if(T.linked == src)
 			T.linked = null
+	if(GLOB.ntnet_global)
+		for(var/obj/structure/machinery/ntnet_relay/R as anything in GLOB.ntnet_global.relays)
+			if(R.linked == src)
+				R.linked = null
 	if(entry_points)
 		entry_points.Cut()
 	for(var/obj/structure/machinery/ship_weapon/SW in ship_weapons)
@@ -150,6 +154,9 @@ GLOBAL_DATUM(map_overmap, /area/overmap)
 		H.attempt_hook_up(src)
 	for(var/obj/structure/machinery/telecomms/T in SSmachinery.all_telecomms)
 		T.attempt_hook_up(src)
+	if(GLOB.ntnet_global)
+		for(var/obj/structure/machinery/ntnet_relay/R as anything in GLOB.ntnet_global.relays)
+			R.attempt_hook_up(src)
 
 /obj/effect/overmap/visitable/proc/get_areas()
 	return get_filtered_areas(list(/proc/area_belongs_to_zlevels = map_z))

code/modules/overmap/ships/computers/ship.dm

@@ -254,6 +254,20 @@ somewhere on that shuttle. Subtypes of these can be then used to perform ship ov
 /obj/structure/machinery/computer/ship/proc/viewing_overmap(mob/user)
 	return (WEAKREF(user) in viewers) || (linked && (WEAKREF(user) in linked.navigation_viewers))
 
+/obj/structure/machinery/computer/ship/proc/unlook_all_viewers()
+	if(!LAZYLEN(viewers))
+		return
+
+	var/list/current_viewers = viewers.Copy()
+	for(var/datum/weakref/W in current_viewers)
+		var/mob/M = W.resolve()
+		if(M)
+			unlook(M)
+			if(M.machine == src)
+				M.unset_machine()
+		else
+			LAZYREMOVE(viewers, W)
+
 /obj/structure/machinery/computer/ship/CouldNotUseTopic(mob/user)
 	. = ..()
 	unlook(user)
@@ -274,6 +288,7 @@ somewhere on that shuttle. Subtypes of these can be then used to perform ship ov
 		return SEE_THRU
 
 /obj/structure/machinery/computer/ship/Destroy()
+	unlook_all_viewers()
 	if(linked)
 		linked = null
 	if(connected)
@@ -284,13 +299,6 @@ somewhere on that shuttle. Subtypes of these can be then used to perform ship ov
 	sensor_ref = null
 	identification = null
 	QDEL_NULL(sound_token)
-	if(LAZYLEN(viewers))
-		for(var/datum/weakref/W in viewers)
-			var/M = W.resolve()
-			if(M)
-				unlook(M)
-				if(linked)
-					LAZYREMOVE(linked.navigation_viewers, W)
 	. = ..()
 
 /obj/structure/machinery/computer/ship/on_user_login(mob/M)