fix: correct entity network offsets

[HashimTheArab]

Verified values from RE BDS

Summary

• Correct the player, item, and falling-block network offsets.
• Use the sleeping-player offset while a player is in bed.
• Apply entity offsets consistently to spawn, movement, teleport, respawn, dimension-change, and inbound player-position paths.
• Use the player type's network offset for initial game data instead of duplicating a rounded constant.

Why

Dragonfly applied entity offsets to movement packets but not all packets that carry entity positions. Some offset constants were also rounded or based on entity bounds rather than their network positions. This could make initial spawns and subsequent movement disagree about an entity's base position.