[Actions] Restore device state changed by an automation

[emi-ran]

Feature

Let an automation restore system state captured before it changed it.

Scope

Initial restoreable state: sound profile, media volume, brightness plus auto-brightness, auto-rotate, DND, dark theme, Wi-Fi, and Bluetooth.

Design constraints

• Capture only state that an action will change, immediately before that action succeeds. Record a provenance token tied to rule/run/action; do not snapshot unrelated device state.
• Define restoration trigger explicitly: manual restore, rule completion, inverse trigger, profile deactivation, or configurable option. Avoid automatic rollback that overwrites a user change made after execution.
• Before restoring, compare current state with value FlowPilot last applied. If user/OEM changed it, warn/skip rather than clobber it.
• Store bounded, encrypted-at-rest snapshots with TTL and cleanup. Never include webhook, phone, SMS, notification, or clipboard data.
• Every capture/restore needs capability checks and readback. Partial restore must be reported per field.

Acceptance criteria

• Restore returns supported states to captured values when unchanged by user.
• User change after automation prevents silent overwrite.
• Process restart, expired token, missing permission, and unsupported state fail honestly.

Verification

• Unit tests for snapshot lifecycle, compare-and-restore, TTL, and partial failures.
• Xiaomi smoke tests per state, including Shizuku/permission denial and manual user override.