Correct alarm data findings from byte tests

The alarm station byte is shared and follows the current radio station, so
remove the per-alarm control. Remove the FM sound option, as writing it just
turns on the radio mode. Record how the MCU treats each DP127 byte.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

wake-up-light-ii.yaml

@@ -22,7 +22,7 @@ external_components:
   - source:
       type: git
       url: https://mangavalk.com/mangavalk/esphome-wake-up-light-ii.git
-      ref: v1.0.1
+      ref: v1.0.2
     components: [uart]
     refresh: 1d
 
@@ -266,14 +266,18 @@ tuya:
     # [00] enabled
     # [01:02] time = minutes since midnight, big-endian
     # [03] repeat days: bit 0 = Monday ... bit 6 = Sunday, 0 = one time
-    # [04] ring duration (Tuya says 10-20, this lamp reports 30)
-    # [05] mode: 0=sound, 1=sound+light, 2=radio, 3=radio+light
-    # [06] sound (this project also observed 8=FM)
-    # [07] sound volume 1..16
-    # [08] radio station 1..60
-    # [09] sunrise lead time in minutes, 10..60
-    # [10] brightness after sunrise, 1..20
-    # [11] snooze: 0=allowed, 1=not allowed
+    # [04] ring duration (Tuya says 10-20, this lamp reports 30; any value is kept)
+    # [05] mode bits: bit 0=light, bit 1=radio. Values above 3 are ignored.
+    # [06] sound 0..7. Writing 8 or more turns on the radio bit and resets it to 1.
+    #      Locked at 1 in radio modes.
+    # [07] volume 1..16 (any value is kept)
+    # [08] radio station. Not per alarm: every write sets all 4 to the current
+    #      radio station, so don't try to set it here.
+    # [09] sunrise lead time in minutes, 10..60 (any value is kept)
+    # [10] brightness after sunrise, 1..20. Forced to 0 without the light bit, and
+    #      0 clears the light bit.
+    # [11] snooze: 0=allowed, 1=not allowed. Values above 1 become 1.
+    # The MCU doesn't range-check most bytes, so the controls must.
     - sensor_datapoint: 127
       datapoint_type: raw
       then: