Add accessibility option for larger UI scale and stronger readability

[NickTheDevOpsGuy]

Summary

Phuzzle already cares about accessibility, but players with low vision would benefit from a stronger readability mode beyond current theme and color-friendly settings.

Scope

• Add an accessibility toggle for larger interface scale and stronger text readability.
• Tune critical screens such as home, setup modals, play HUD, completion, and stats.
• Keep the mobile layout stable even with larger text.

Acceptance Criteria

• Players can enable a readability-focused UI mode from settings.
• Text, buttons, and critical HUD elements become easier to read without clipping.
• The mode works on mobile and desktop.
• At least one accessibility regression test is added.

Bucket

Good first issue or smaller accessibility-focused feature