SendAnywhere 1.0.0 v4

Update Parcel Placement Improvements

Fixed / Improved 

• Improved detection of solid ground beneath parcel locations.
  - Added support for coordinates pointing directly at full ground blocks.
  - Added handling for coordinates pointing at the air block above solid ground.
  - Added limited downward ground searching for suitable locations.
  - Rechecks placement safety when delivery is accepted.

 Included Features
- Private delivery requests with Accept / Decline.
- Four-digit delivery-code verification.
- Custom keypad GUI and locked parcel barrels.
- Player-name autocomplete.
- Parcel tracking, cancellations, and item returns.

 Known Limitations
- Land-claim integrations are not implemented.
- Certain partial and non-solid blocks may be rejected.
- Compatibility with each Paper 1.21.x release requires individual testing.