Shortcuts screen style and content issues

[bokuwagaijin]

Page doesn't render properly in dark mode due to icons still being light mode. Additionally the mac keyboard shortcuts aren't correct.

Problems

• Dark mode: Icon set remains styled for light theme, causing low contrast and visibility issues.
• Content: macOS keyboard shortcuts listed on the shortcuts page are incorrect.

Expected

• Icons adapt correctly to dark mode with proper contrast.
• macOS shortcuts match current Copilot documentation and VS Code/JetBrains mappings.

Scope

• Update CSS or asset handling to ensure icon colors/styles switch for dark mode.
• Fix incorrect macOS shortcut entries in the shortcuts markdown.

Acceptance Criteria

• In dark mode, all icons are legible with sufficient contrast and visually consistent with theme.
• Shortcuts page shows correct macOS mappings for Accept suggestion, Reject suggestion, Next/Previous suggestion, Alternative suggestions, Accept next word, Inline chat triggers, and Open chat view.
• Changes pass visual check in both light and dark mode.

Additional Notes

• Check docs/99-Additional-Resources/01-Keyboard-Shortcuts.md for incorrect macOS shortcuts.
• Verify icon components under src/components and CSS in src/css/custom.css and src/components/**/styles.module.css for theme-specific styles.

[bokuwagaijin]

@github-copilot-agent Please take ownership of this issue and generate a PR to:

1. Fix dark mode icon styling to ensure proper contrast
2. Correct macOS keyboard shortcuts in docs/99-Additional-Resources/01-Keyboard-Shortcuts.md

Acceptance criteria are in the issue body. Thank you!