test: add three probes to bisect the remaining failure

Routing the network components changed nothing, so the fault is further
down. The wiki documents no network components at all, so there is
nothing to look up and the remaining possibilities have to be separated
empirically.

Each probe drives its own indicator, and an indicator draws while its
toggle is off, so a visible icon means that probe failed:

  A (mine)  ThresholdToggle misbehaves, no network involved
  B (crew)  a mod-defined category carries nothing, broadcast and
            received on the same part
  C (EMP)   receiving fails even for thermal_load_dissipation, which
            this very radiator already broadcasts

Also switch the real thresholds from MinAmount = 0.5 to the
MaxAmount = 0 / Invert form the thermal pump uses. The signals are only
ever 0 or 1 so it is equivalent, and it removes a variable.

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_011oLWY1G6S8U35bi2FxVWni

mod.rules

@@ -16,7 +16,7 @@
 
 ID = ganter.auto_radiator
 Name = "Auto Radiator"
-Version = 1.3.0
+Version = 1.4.0
 CompatibleGameVersions = ["0.30.4c", "0.30.4"]
 ModifiesGameplay = true
 Author = "Tobias Ganter"
@@ -85,6 +85,9 @@ Actions
 			[NetworkedHeatBuffer, AutoRad_HoldSignal, 0]
 			[NetworkedHeatBuffer, AutoRad_ThermalAmmoSignal, 0]
 			[NetworkedHeatBuffer, AutoRad_ForceVentSignal, 0]
+			[NetworkedHeatBuffer, AutoRad_ProbeBroadcast, 0]
+			[NetworkedHeatBuffer, AutoRad_ProbeReceive, 0]
+			[NetworkedHeatBuffer, AutoRad_ProbeVanillaCat, 0]
 		]
 	}
 
@@ -180,6 +183,35 @@ Actions
 					Size = [1, 1]
 				}
 			}
+			// Probe A: mine icon visible -> ThresholdToggle itself misbehaves.
+			{
+				Toggle = AutoRad_ProbeThresholdOK
+				AtlasSprite
+				{
+					File = &/INDICATORS/NoMines
+					Size = [1, 1]
+				}
+			}
+			// Probe B: crew icon visible -> a mod-defined category carries
+			// nothing, even broadcast and received on the same part.
+			{
+				Toggle = AutoRad_ProbeSelfLoopOK
+				AtlasSprite
+				{
+					File = &/INDICATORS/NoCrew
+					Size = [1, 1]
+				}
+			}
+			// Probe C: EMP icon visible -> receiving fails even for a category
+			// vanilla already broadcasts on this very part.
+			{
+				Toggle = AutoRad_ProbeVanillaCatOK
+				AtlasSprite
+				{
+					File = &/INDICATORS/NoEmp
+					Size = [1, 1]
+				}
+			}
 		]
 	}
 ]