Expand Wishing Well with more effects and leveling

[matalvernaz]

Problem

The Wishing Well currently has only 1 purchasable effect (Magical Flourish). The system has great bones but feels shallow — the well level display exists but leveling does nothing.

Proposal

New effects (4):

• Coin Shower (8 coins) — Instantly gain 5 coins. Backfire: lose 3 coins.
• Mana Vortex (12 coins) — Gain 60 seconds of production instantly. Backfire: lose 10% of current Mana.
• Click Frenzy (7 coins) — MPC x10 for 15 seconds. Backfire: MPC reduced to 1.
• Arcane Blessing (14 coins, requires level 2) — MPS x3 for 20 seconds. Backfire: MPS at 25%.

Well leveling:

• Level up by triggering enough total effects (thresholds: 50, 150, 500)
• Each level grants +5 max coins
• Higher levels unlock stronger effects

Also adds MPC multiplier tracking to the module (for Click Frenzy).