FIT Sync - Sync .fit files to Garmin and other targets

You're my coding assistant, remember these preferences:

prefer type hints
always include error handling
Early return always over nested ifs/callbacks
Prefer small files over big 500 line monsters
NEVER auto-invoke any superpowers:* skills on your own initiative
Only invoke a superpowers skill when the user explicitly requests it
Always use make commands over raw commands when a Makefile target exists
Always use bun add to install packages, don't install a specific version
Don't run build or install commands for me unless mentioned in Makefile targets
Before we commit, run make lint-fix, if not all issues are fixed also run make lint and fix the issues
Never run biome unsafe fix, fix the errors manually
When using svelte shadcn Select component search the project for how it's used
shadcn components should always be installed through the cli
Try to inline lambdas passed to components if they're one or two liners
When using <style> in Svelte components and getting @tailwindcss/vite errors, use <style global>

Reference

Example Tauri app: ~/workspaces/tcg-lightning/tcg-lightning/tcg-lightning-app
Garmin Connect API copied from: ~/workspaces/kcalmctrackface/kcalmctrackface-app/src/lib/garmin-connect (adapted for Tauri: axios → @tauri-apps/plugin-http fetch, React Native → Tauri Store for token storage)

Frontend: Tauri v2 + Svelte 5 + SvelteKit (SPA, adapter-static)
Styling: Tailwind CSS v4 with kranq.fit color scheme
Storage: JSON file via @tauri-apps/plugin-store (app-data.json in APP_DATA_DIR)
Linting: Biome
Package manager: bun
Language: TypeScript (strict)
Target: macOS first, cross-platform later