Fate Prototype

### Changes
- Reworked servant VFX to use cleaner vanilla-style particles instead of heavy custom client VFX.
- Removed old aura/ring/beam texture-based effects and simplified combat visuals.
- Added a smoother servant summon reveal animation with class-colored particles.
- Added the Master's Book item and GUI with servant class, HP, prana, orders, cooldowns, command spells, and relic info.
- Added the servant command wheel with follow, guard, patrol, hold fire, target nearest, and protect master orders.
- Added the downed system: servants can fall instead of instantly dying, and can be revived once through life transfer.
- Shortened and fixed downed behavior, including cooldowns no longer resetting while downed.
- Improved the downed servant pose so it looks more natural.
- Improved servant HUD with HP, state, downed timer, and Noble Phantasm status.
- Improved Archer combat: bow and blades now swap through real inventory slots instead of appearing from nowhere.
- Archer can now use a vanilla bow if the signature Archer Bow is missing.
- Archer's shooting pose now only activates when a bow is actually held in the main hand.
- Improved servant targeting, guard behavior, and combat reactions.
- Refactored command code into smaller command modules for easier maintenance.
- Fixed multiple visual, AI, and combat behavior issues.