Upgrade to buttplug v5, add battery level display, bump to 0.2.0

buttplug-wasm@3.0.0 still declares buttplug@^4.0.2 as its dependency,
and v5 changed the OutputCmd wire shape (Value: number[] -> number) -
a real protocol difference, not just a type mismatch. Confirmed by
testing against real Lovense hardware that device control still works
in practice, so the bump stands; the risk is documented at the
client.connect() cast in case a future device/build doesn't fare as
well.

Also fixes a Map vs ReadonlyMap mismatch in the version-agnostic
feature-type extraction (v4 returns Map, v5 returns ReadonlyMap) that
surfaced while making this change, and adds a battery indicator to each
connected device's card - reads once on connect, refreshes every 60s,
using device.hasInput("Battery") to detect support.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01W8WkFF5ppURBAB918593Eb

lib/buttplug/store.ts

@@ -10,12 +10,15 @@ interface ButtplugStoreState {
   devices: Record<number, ConnectedDeviceInfo>;
   /** Last-known slider value per `${deviceIndex}:${featureIndex}`, for UI display only. */
   actuatorValues: Record<string, number>;
+  /** Last-known battery reading (0-1) per device index; absent until first read completes. */
+  batteryLevels: Record<number, number | null>;
   error: string | null;
   setConnected: (connected: boolean) => void;
   setScanning: (scanning: boolean) => void;
   upsertDevice: (device: ConnectedDeviceInfo) => void;
   removeDevice: (index: number) => void;
   setActuatorValue: (deviceIndex: number, featureIndex: number, value: number) => void;
+  setBatteryLevel: (deviceIndex: number, level: number | null) => void;
   setError: (message: string | null) => void;
   reset: () => void;
 }
@@ -25,6 +28,7 @@ export const useButtplugStore = create<ButtplugStoreState>((set) => ({
   scanning: false,
   devices: {},
   actuatorValues: {},
+  batteryLevels: {},
   error: null,
   setConnected: (connected) => set({ connected }),
   setScanning: (scanning) => set({ scanning }),
@@ -33,12 +37,16 @@ export const useButtplugStore = create<ButtplugStoreState>((set) => ({
     set((s) => {
       const devices = { ...s.devices };
       delete devices[index];
-      return { devices };
+      const batteryLevels = { ...s.batteryLevels };
+      delete batteryLevels[index];
+      return { devices, batteryLevels };
     }),
   setActuatorValue: (deviceIndex, featureIndex, value) =>
     set((s) => ({
       actuatorValues: { ...s.actuatorValues, [actuatorKey(deviceIndex, featureIndex)]: value },
     })),
+  setBatteryLevel: (deviceIndex, level) =>
+    set((s) => ({ batteryLevels: { ...s.batteryLevels, [deviceIndex]: level } })),
   setError: (message) => set({ error: message }),
-  reset: () => set({ connected: false, scanning: false, devices: {}, actuatorValues: {} }),
+  reset: () => set({ connected: false, scanning: false, devices: {}, actuatorValues: {}, batteryLevels: {} }),
 }));