[lasers]

Changes

Spell mana cost (battle()): mana -= 10 - manaCost made 15/20-cost spells add mana. Each attack now costs the base 10 plus the spell's cost:

int manaCost = 10 + hero.equippedSpell.manaCost;

⚠️ This is my guess at the intent; adjust if you meant something else.

Weapon attack: when mana came back mid-battle (auto-potion), the "attack decreased" flag was cleared without giving back the 3 attack, so the loss was permanent. It's now restored when the flag is cleared.

Companion: a dead companion no longer takes damage (its HP stays at 0 instead of going negative), and "has fallen" prints once instead of every enemy turn.

Level-up (gainXP()):

• XP above the threshold is kept: xp -= level * 50 instead of xp = 0.
• Max HP/mana are raised before the level-up heal, so the new points get filled.

Testing

A throwaway test (not committed) ran 200 random seeds and checked:

• XP carry-over and the level-up heal
• a 20-cost spell lowers mana instead of raising it
• weapon attack is back to normal after mana returns mid-battle
• the companion death message prints at most once, and companion HP never goes below 0

It fails on main and passes on this branch.

Question

The shop between floors charges 20 gold for the small potion, while the potion shop sells it for 15. Is that intentional? I didn't change it.

Fixes #4