HyAmmo

### New Features
- Added full crossbow compatibility so all HyAmmo arrow types now apply through projectile-capability detection (bows, crossbows, and future modded projectile weapons).
- Added an external projectile compatibility layer with defensive fallback handling for unknown/missing arrow metadata so HyAmmo effect logic can layer on top of other projectile mods.
- Added progressive NPC arrow drop scaling with tiered weighted tables and config-driven thresholds (`EnableProgressiveNpcArrowDrops`, `NpcDropTier2MinInitialHealth`, `NpcDropTier3MinInitialHealth`, `NpcDropTier4MinInitialHealth`).

### Fixes
- Fixed random arrow spawn behavior from non-arrow projectile sources (including rubble-style throws) by tightening projectile source classification and fallback gating.
- Fixed stone arrow knockback reliability by switching to additive velocity application and introducing configurable stone knockback scaling (`StoneKnockbackMultiplier`).
- Fixed NPC drop eligibility logic so passive/animal-style entities no longer receive hostile arrow drop rolls.
- Fixed target-server compatibility metadata by pinning `ServerVersion` to `2026.02.17-255364b8e`.
- Fixed server update API breakage by adding `AssetModule.registerPack` compatibility support for both legacy 3-arg and newer 4-arg signatures.