Add terminal shortcut

[jsgrrchg]

Summary

Adds a dedicated terminal shortcut so power users can open a new terminal tab with Cmd+R on macOS and Ctrl+R on Linux/Windows when the developer terminal is enabled.

Details

• Adds new_terminal to the central shortcut registry and settings shortcut list.
• Wires the shortcut to the existing developer:new-terminal-tab command so it reuses the current developer mode and terminal enabled guard.
• Adds the native macOS menu accelerator without introducing an Electron reload role.
• Covers shortcut formatting, matching, opening behavior, and disabled-terminal behavior in tests.

Validation

• npm test -- src/app/shortcuts/format.test.ts src/App.noteWindow.test.tsx
• npx tsc -b --pretty false
• git diff --check
• Verified no role: reload was added.