feat(alarm): add music alarm scheduling with playlist and random playback options

[0xarchit]

Problem

Metrolist did not provide a built-in music alarm flow for users who want playback to start at a scheduled time.

Solution

This PR introduces an alarm feature integrated into app settings and playback flow.

Included changes

• Added alarm settings UI and navigation entry in Settings.
• Added scheduling logic using Android AlarmManager.
• Added alarm trigger receiver and reschedule receiver for system events (boot/time change/package replace).
• Added persistent alarm preferences (enabled, time, playlist id, random mode, next trigger).
• Added required manifest declarations and permissions for alarm + wake behavior.
• Added localized strings for alarm UI in res/values/metrolist_strings.xml.

User-facing behavior

• User can enable/disable alarm.
• User can choose alarm time.
• User can select playlist source.
• User can enable random track mode for playlist alarms.

Testing

• Built successfully with:
  • ./gradlew :app:assembleuniversalFossDebug
• Installed and tested on physical Android device.
• Verified:
  • alarm scheduling
  • trigger execution path
  • playlist selection + random toggle behavior
• Testing device details:
  • Xiaomi redmi K50i / Redmi Note 11T Pro / POCO X4 GT
  • codename: xaga
  • Android 14
  • 6 GB RAM + 128 GB storage varient

Notes

• Exact alarm behavior depends on Android version/device policy and permission state.
• OEM battery optimization settings can still affect background reliability on some devices.

Screenshots

• Alarm configuration section in settings

• Alarm settings screen