feat(meta): CodeplugMeta.radioProfile for import provenance

[pskillen]

Problem

When importing an OpenGD77 CPS export, the app does not record which radio profile the export likely came from. Export-time profile selection (#43 follow-up) works better if import can suggest a default profile.

Intended outcome

• Optional CodeplugMeta.radioProfile (e.g. opengd77/baofeng-1701) set on import when adapter/profile is known.
• Export page pre-selects profile from meta when present.
• Model stays radio-agnostic — profile is metadata only, not embedded in channel/zone entities.

References

• docs/reference/opengd77/radios/README.md
• src/models/codeplug.ts — CodeplugMeta
• Discovered during docs: authoritative OpenGD77 CPS CSV field reference under docs/reference/opengd77/ #43