Add HealAllYourPokemon mechanic for multi-Pokemon healing attacks

[bcollazo]

Summary

This PR implements support for attack mechanics that heal all of your Pokémon, enabling attacks like Audino's "Healing Light" and Mega Audino-EX's "Heartfelt Shine" to function correctly.

Key Changes

• New Mechanic Variant: Added HealAllYourPokemon { amount: u32 } to the Mechanic enum to represent attacks that heal multiple friendly Pokémon
• Attack Resolution: Implemented heal_all_your_pokemon_attack() function that applies damage to the opponent's active Pokémon while healing all friendly Pokémon in play
• Helper Function: Added heal_all_pokemon() utility to iterate through all in-play Pokémon for a player and apply healing
• Effect Mapping: Registered two effect text mappings:
  • "Heal 10 damage from each of your Pokémon." → HealAllYourPokemon { amount: 10 }
  • "Heal 30 damage from each of your Pokémon." → HealAllYourPokemon { amount: 30 }
• Test Coverage: Added comprehensive tests for both Audino and Mega Audino-EX attacks, verifying correct damage and healing behavior

Implementation Details

The heal_all_your_pokemon_attack() function uses the existing active_damage_effect_doutcome() pattern to ensure the opponent takes damage while simultaneously healing all friendly Pokémon. The healing is applied to every Pokémon slot (active and benched) that contains a Pokémon, matching the intended game mechanics.

https://claude.ai/code/session_016skACacbdAnKXSwzkzuBqK