Redesign Sud schedule format: separate ramp/hold keys with defaults

Steps now declare a "ramp" or "hold" key instead of a flat "type", and
unspecified fields (including nested stirrer settings) fall back to a
new top-level default.step structure. Stirrer config is now
interval_time/on_ratio, mapping directly onto AStirrer's cycle
time/duty cycle instead of separate on/off durations. Update
components/sud.py, tasks/sud.py, the Sud demo, sude/sud_0010.json, and
the README to match.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01CgR9tPaSzFkAwRAUyeaaCD

components/sud.py

@@ -20,6 +20,31 @@ class SudState(Enum):
 	DONE = 4
 
 
+def _merge_defaults(default, override):
+	"""Deep-merges override onto default, recursing into nested dicts so
+	values missing from override fall back to default's at every level."""
+	merged = dict(default)
+	for key, value in override.items():
+		if key in merged and isinstance(merged[key], dict) and isinstance(value, dict):
+			merged[key] = _merge_defaults(merged[key], value)
+		else:
+			merged[key] = value
+	return merged
+
+
+def _build_step(defaults, raw_step):
+	"""Fills in a schedule step with default.step's values. A step is a
+	ramp or a hold depending on which of those keys it specifies; the other
+	is left out rather than synthesized from defaults."""
+	step = {}
+	for key in ('descr', 'user_message', 'user_wait_for_continue'):
+		step[key] = raw_step.get(key, defaults.get(key))
+	for key in ('ramp', 'hold'):
+		if key in raw_step:
+			step[key] = _merge_defaults(defaults.get(key, {}), raw_step[key])
+	return step
+
+
 class Sud(AttributeChange):
 	def __init__(self, path):
 		AttributeChange.__init__(self)
@@ -28,7 +53,9 @@ class Sud(AttributeChange):
 
 		self.name = data.get('Name', '')
 		self.description = data.get('Description', '')
-		self.schedule = data['schedule']
+
+		step_defaults = data.get('default', {}).get('step', {})
+		self.schedule = [_build_step(step_defaults, raw) for raw in data['steps']]
 
 		self.pot_mass = data.get('pot_mass', 0)
 		self.pot_material = data.get('pot_material')
@@ -84,10 +111,10 @@ class Sud(AttributeChange):
 			return
 
 		next_step = self.schedule[self.index]
-		if next_step['type'] == 'heat':
+		if 'ramp' in next_step:
 			self.state = SudState.RAMPING
 		else:
-			self.hold_remaining = next_step.get('duration', 0)
+			self.hold_remaining = next_step['hold'].get('duration', 0)
 			self.state = SudState.HOLDING
 
 		self.user_message = next_step.get('user_message')