Adjust spell casting times

[Hartwich]

Goal

Handle casting time changes separately so they stay reviewable.

Codex Auftrag

Adjust Magic Duell spell casting times to improve pacing.

Focus

• identify all current casting time values
• make fast/simple spells feel responsive
• make strong spells readable and avoid instant unfair hits
• keep changes small

Acceptance Criteria

• Casting time values are easy to find and adjust.
• Changed values are documented in the PR description.
• No unrelated skill logic is changed.
• npm run typecheck passes.

Safety

Do not add copyrighted, unclear, or unreviewed third-party assets or content.