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/types.ts

@@ -20,6 +20,7 @@ export interface ConnectedDeviceInfo {
   name: string;
   displayName?: string;
   actuators: ActuatorInfo[];
+  hasBattery: boolean;
 }
 
 /** A single dispatched command, timestamped relative to session start. */