Device: Add missing features for AirPods Max 2 and Powerbeats Pro 2

[d4rken]

What changed

• AirPods Max 2 now shows all its supported settings (adaptive noise control, conversation awareness, personalized volume, listening mode customization) instead of showing the same limited set as the original Max.
• Powerbeats Pro 2 now shows sleep detection and ear detection toggle options.
• Toggling auto-play or auto-pause now automatically keeps the device's ear detection setting in sync, so users don't need to manage it separately.

Technical Context

• AirPods Max 2 shipped with the H2 chip (March 2026) but was using the same PodModel.Features as Max 1/USB-C (H1 chip). This meant adaptive ANC, conversation awareness, personalized volume, and listening mode cycle were all hidden. Adding needsInitExt also changes protocol behavior — the extended init packet (0x4D) is now sent during AAP handshake for Max 2.
• The ear detection toggle (0x0A) had full protocol and ViewModel support but was never wired into the UI. Instead of exposing it as a separate setting (which would confuse users since CAPod reads ear state from BLE beacons regardless of this device setting), it's now synced automatically: enabled when either auto-play or auto-pause is active, disabled when both are off. The sync is guarded on hasEarDetectionToggle, AAP readiness, and pro status.
• Added flag invariant tests (adaptiveAnc -> ancControl, sleepDetection -> earDetection, etc.) to catch future drift when new models are added.