Add Keyboard Abyss import/export tab

[cormoran]

Summary

• add local Keyboard Abyss package dependencies
• add an Import/Export tab with Abyss OAuth session storage login
• load connected ZMK keyboard data, list Abyss keymaps, preview diffs, and write diffs through the Abyss ZMK adapter

Verification

• npm run lint
• npm run format:check
• npm run build
• opened the local app in demo mode and verified the Import/Export tab renders