feat(charging): add configurable charging limit and pass-through control

[alterkeyy]

Summary

• Add a configurable 20–100% battery charge limit, using Samsung battery protection at supported levels and the device charge threshold for other levels.
• Add a setting to restore the preferred limit after restart and a Quick Settings tile to pause charging at the current battery level.
• Add charging policy and control engine unit tests, plus user-facing guidance.

Validation

• ./gradlew :app:testDebugUnitTest :app:assembleDebug --offline (passed)
• Device behavior was not tested; applying the controls requires root, and pass-through charging requires a compatible USB PD PPS charger.

Acknowledgement

• OneDesign
• fvffv/samsung-feature-extension