Reverse Cursed Experience

Added a new Technique Progression (Tier 2) system: after healing enough over time, RCT XP upgrades to a stronger mode that heals more and costs less XP, but builds strain faster so you reach overload sooner. Reworked the client VFX into a cleaner aura-style particle effect (fewer particles, spread around the player instead of clumping at the center). Fixed an issue where particles could briefly appear when activating the technique at full health.