Pablo dev Backlight & various mods. Error corrections

[PabloMartin97]

1. Restored can.json to match BoostedMoose content, keeping only the added signal_sensors block.
2. Recovered missing upstream profile files into my branch: can.json, rti.json, swc.json.
3. Reverted package-lock.json project version.
4. Merged .gitignore: Kept all entries from upstream/master. Added my entries (frontend/node_modules/, .DS_Store, *.pyo, .vscode/).

[Tigo2000]

• Fix repeated app settings loop
• Prevent crash in Settings.tsx if a config key is missing
• Added config migration, so that if you load the app using an outdated config, it automatically merges the new config into the current one
• Fix vehicle selection not showing any vehicles on an empty/no config