Simplify Pot: drop gain/theta params, seed initial temp from ambient

[Pot] - removed the gain (efficiency) factor and the separate
"theta" initial-temperature param; Pot now starts at theta_amb and
set_power()/get_power() operate on p_in directly. Added
set_ambient_temperature() for live ambient updates. Dropped the
now-unused "theta"/"gain" keys from Model/Plant in config.json.sim
and config.json.templ (also fixes a JSON syntax error in
config.json.templ: trailing commas left over after removing "gain"
made Model/Plant fail to parse).
[Sensor] - fix missing space in TempSensorSim.temperature()'s
offset/variance expression (cosmetic, no behavior change).

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

components/plant/pot.py

@@ -8,9 +8,7 @@ class Pot(APlant):
 
 		self.e = 0
 		self.x = 0
-
-		# Plant power gain (efficiency)
-		self.gain = params['gain']
+		self.p_pot = 0
 
 		# Plant specific thermal capacity [W*s/(kg*K)]
 		self.C = params['C']
@@ -27,18 +25,16 @@ class Pot(APlant):
 		self.Td = params['Td']
 
 		# Plant temperature [°C]
-		self.temp = params['theta']
+		self.temp = theta_amb
 
 		# Ambient temperature [°C]
 		self.theta_amb = theta_amb
 
 		# Set power [W]
-		self.power_set = 0
+		self.p_in = 0
 
 		# Plant delay [s]
 		self.delay = delay.Delay(dt, self.Td, 0)
-		self.p_in = 0
-		self.p_pot = 0
 
 	def initial(self, temp):
 		self.temp = temp
@@ -47,7 +43,6 @@ class Pot(APlant):
 		pass
 
 	def process(self):
-		self.p_in = self.gain * self.power_set
 		self.delay.put(self.p_in)
 
 		p_loss = self.L * self.M * (self.temp - self.theta_amb)
@@ -58,11 +53,14 @@ class Pot(APlant):
 	def is_activated(self):
 		return True
 
+	def set_ambient_temperature(self, theta_amb):
+		self.theta_amb = theta_amb
+
 	def set_power(self, power):
-		self.power_set = power
+		self.p_in = power
 
 	def get_power(self):
-		return round(self.power_set, 1)
+		return round(self.p_in, 1)
 
 	def get_temperature(self):
 		return self.temp