fix: single-owner battery debounce with hardened input handling

headsetcontrol/lib/hsc.luau

@@ -14,10 +14,13 @@ local CAP_KEY = {
 
 local config = { device = "", mock = false, wake_sink = "" }
 
+local zeroStreak = 0
+
 function M.init(cfg)
   config.device = cfg.device or ""
   config.mock = cfg.mock or false
   config.wake_sink = cfg.wake_sink or ""
+  zeroStreak = 0
 end
 
 function M.isMock()
@@ -224,18 +227,23 @@ function M.fetchConnected(cb)
   end)
 end
 
-local zeroStreak = 0
-
 -- Debounces transient 0% readings: a lone 0 between good readings is
 -- normalized to unavailable (no false widget 0% or warning); two 0s in a
--- row pass through as a genuinely empty battery. Each entry keeps its own
--- streak since every entry gets a separate module instance.
+-- row pass through as a genuinely empty battery. Single owner is the
+-- service entry (service.luau); the panel publishes its one-shot wake
+-- read raw. Non-table input or a missing/non-numeric level resets the
+-- streak and normalizes to unavailable, as does a nil reading.
 function M.stableBattery(battery)
-  if battery == nil then
+  if type(battery) ~= "table" then
     zeroStreak = 0
     return { status = "BATTERY_UNAVAILABLE", level = -1 }
   end
-  if battery.level == 0 then
+  local level = tonumber(battery.level)
+  if level == nil then
+    zeroStreak = 0
+    return { status = "BATTERY_UNAVAILABLE", level = -1 }
+  end
+  if level == 0 then
     zeroStreak = zeroStreak + 1
     if zeroStreak >= 2 then
       return battery

headsetcontrol/panel.luau

@@ -110,7 +110,7 @@ function onWake()
     end
     hsc.fetchStatus(function(status)
       if status ~= nil then
-        noctalia.state.set("battery", hsc.stableBattery(status.battery))
+        noctalia.state.set("battery", status.battery or { status = "BATTERY_UNAVAILABLE", level = -1 })
         noctalia.state.set("chatmix", status.chatmix or 0)
         noctalia.state.set("lastUpdate", noctalia.nowMs())
       end

headsetcontrol/service.luau

@@ -36,7 +36,7 @@ local function handleStatus(status)
       return
     end
     noctalia.state.set("error", "unavailable")
-    noctalia.state.set("battery", { status = "BATTERY_UNAVAILABLE", level = -1 })
+    noctalia.state.set("battery", hsc.stableBattery(nil))
     noctalia.state.set("chatmix", 0)
     return
   end