fix(washer): stale idle progress%, add detergent/softener dosing entities (#9)

progress_percentage lacked the active-state gate already applied to
progress/cycle_active/finish_time, so it kept showing a stale device value
(e.g. 1%) while idle -- now zeroed the same way. Shared by dryer/dishwasher/
oven via operational.py's OPERATIONAL_STATE.

Also exposes detergent/softener auto-dispense quantity, water hardness/
concentration, and low-reservoir alarms from /course/vs/0's options array,
using the same decode/RMW helpers already used for course selection and
drum-clean tracking. Gated by exists_fn so washer models without these
fields (e.g. the existing test fixture) are unaffected.

Water consumption is unaffected -- common.WATER_METER is already wired
into the washer registry; this reporter's device just doesn't expose
/water/consumption/vs/0.

tests/test_operational_capability.py

@@ -8,6 +8,22 @@ def test_machine_state_maps_samsung_to_ocf():
     assert ms.value_fn('Ready') == 'idle'
 
 
+class TestProgressPercentage:
+    """issue #9: device firmware leaves progressPercentage stale (e.g. '1')
+    after a cycle ends instead of resetting it, so it must be gated on
+    active state the same way `progress`/`cycle_active`/`finish_time` are."""
+
+    def test_zeroed_when_not_active(self):
+        desc = next(e for e in OPERATIONAL_STATE.entities if e.key == 'progress_percentage')
+        rep = {'x.com.samsung.da.state': 'Ready', 'x.com.samsung.da.progressPercentage': '1'}
+        assert desc.rep_fn(rep) == 0
+
+    def test_passes_through_when_active(self):
+        desc = next(e for e in OPERATIONAL_STATE.entities if e.key == 'progress_percentage')
+        rep = {'x.com.samsung.da.state': 'Run', 'x.com.samsung.da.progressPercentage': '42'}
+        assert desc.rep_fn(rep) == 42
+
+
 class TestDelayFieldFallback:
     def test_reads_delay_end_time_when_delay_start_time_absent(self):
         from custom_components.localthings.registry.capabilities.operational import OPERATIONAL_STATE