Features:
- Add financial year support in reports and transaction lists.
- Unify Deposit/Withdrawal AS transfer, not counted in Income vs Expenses.
- Refine Notification & Autopost switch logic.

Refactors:
- Moved DBPref into SharedPreference for unified preference management.
- Upgrade JDK17

Bug Fixes:
- Minor cleanups across various files and logic.
- Updated minSdkVersion to 23.

Doc Updates:
- Updated documentation for nested categories, recurring transactions, and JDK17 reference.
