Gale Core encounter tuning

[xefensor]

Goal

Polish the Gale Core encounter so it is readable, fair, and interesting while preserving the Air Temple's wind-focused identity.

Areas to verify

• activation and retaliation behavior
• phase transitions and projectile behavior
• idle movement and return-home logic
• arena escape or terrain-exploitation cases
• difficulty in singleplayer and multiplayer
• reward reliability and duplicate-spawn protection

Completion criteria

• Major encounter exploits and softlocks are addressed
• Phase behavior is understandable through play
• Singleplayer and multiplayer playtests are recorded
• Relevant GameTests are added or updated
• Player-facing changes are added to the changelog

Target: v0.3.0