Corruption → Item Level Scaling

As corruption increases, there should be a chance to increase the base LVL of spawning items.

Rationale

• Higher corruption = harder environment, but currently no reward scaling to match
• Creates a natural risk/reward loop: pushing corruption gives access to stronger loot
• Works alongside corrupted items (Corrupted Items — glitched textures, scaling debuffs, corruption-gated spawns #43) — you get more corrupted items AND higher-level items as corruption climbs
• Prevents the late-game feeling of "why bother" with corruption if loot stays flat

Implementation Ideas

• % chance per item spawn to roll +1 (or more) base LVL, scaling with corruption
• Could be a flat bonus at corruption thresholds, or a continuous probability curve
• Should stack with existing level mechanics, not replace them