Replace stream usage with loops for performance

[Maxlego08]

Summary

• replace Stream and Optional-based pipelines across menu loading, command handling, requirements, and utilities with explicit loops
• reduce intermediate collections by building results via manual iteration in loaders, managers, and placeholder utilities
• update Paper hook implementations to avoid stream usage while preserving caching and dialog construction logic

Testing

• ./gradlew build (fails: dependency io.lumine:Mythic-Dist:5.6.1 returns HTTP 403 from multiple repositories)

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https://chatgpt.com/codex/tasks/task_e_68f4e87bae188321b64480b8f0e1f0a4