Implements "forbidden" areas into atmospherics_sanity unit test (#96141)

## About The Pull Request
I originally just wanted to change the logging for this so that it's
more helpful for mappers, but I realized that this test doesn't cover
the case where a mapper mistakenly connects a illegal area into the air
loop, so I implemented that.

I had to remap Catwalk so that the actual server room was isolated from
everything else. I tried to keep everything intact to the best of my
ability but there simply wasn't much room.

Also, I added a new subtype for the supermatter engine's area, and
included an UpdatePaths file for it. Behaviour should be identical
across the board.
## Why It's Good For The Game
So we can be 100% absolutely definitely sure we didn't attach the waste
loop inside the supermatter engine.

## Mold Spore

<img width="400" height="400" alt="image"
src="https://github.com/user-attachments/assets/f231ba77-097d-4365-b467-17580aceae14"
/>

code/game/objects/effects/landmarks/atmospherics_sanity_landmarks.dm

@@ -21,12 +21,19 @@
 	icon_state = "atmos_sanity_start"
 
 /**
- * Marks an area as a goal for atmospheric connectivity; ignored if the map contains the mark all station areas landmark!
+ * Marks an area as a goal for atmospheric connectivity; ignored if the map contains the mark all station areas landmark
  */
 /obj/effect/landmark/atmospheric_sanity/goal_area
 	name = "Atmospheric Sanity Goal"
 	icon_state = "atmos_sanity_goal"
 
+/**
+ * Marks an area as forbidden from atmospheric connectivity; ignored if the map contains the "mark all station areas" landmark
+ */
+/obj/effect/landmark/atmospheric_sanity/forbidden_area
+	name = "Atmospheric Sanity Forbidden"
+	icon_state = "atmos_sanity_forbidden"
+
 /**
  * Marks an area as ignored for purposes of default station connectivity.
  */