Revert Sud hold "duration" back to minutes

Reverts 19dc7a9 ("Fix Sud hold duration units: seconds, not minutes")
per explicit instruction - duration is minutes again. Re-adds the
*60.0 conversion in Sud._advance() (hold_remaining is ticked in
simulated seconds), the matching conversion in the forecast plot's
_estimate_course(), and flips the README wording back.

README.md

@@ -134,7 +134,7 @@ Files under `sude/` describe a brew's mash schedule ("Sud"): `pot_mass`,
 - a ramp — `"ramp": {"rate": ..., "temp": ...}` — ramp to `temp` at `rate`
   (°C/min), or
 - a hold — `"hold": {"duration": ...}` — hold the current target for
-  `duration` seconds (omit/`0` for an immediate step).
+  `duration` minutes (omit/`0` for an immediate step).
 
 Both `ramp` and `hold` carry a `stirrer` block (`speed`, `interval_time`,
 `on_ratio`): `interval_time: 0` runs the stirrer continuously at `speed`;

client/brewpi_gui.py

@@ -143,7 +143,7 @@ class SudForecastPlot(FigureCanvasQTAgg):
 					t.append(t[-1] + abs(target - theta[-1]) / rate * 60.0)
 					theta.append(target)
 			elif hold is not None:
-				t.append(t[-1] + hold.get('duration', 0))
+				t.append(t[-1] + hold.get('duration', 0) * 60.0)
 				theta.append(theta[-1])
 		return t, theta
 

components/sud.py

@@ -178,7 +178,9 @@ class Sud(AttributeChange):
 		if 'ramp' in next_step:
 			self.state = SudState.RAMPING
 		else:
-			self.hold_remaining = next_step['hold'].get('duration', 0)
+			# "duration" is in minutes; hold_remaining (ticked by tick()'s
+			# simulated-seconds dt) is in seconds.
+			self.hold_remaining = next_step['hold'].get('duration', 0) * 60.0
 			self.state = SudState.HOLDING
 
 		self.user_message = next_step.get('user_message')