[rinaldo-rex]

Summary

• Add Command Code with five-hour/weekly quotas, reset times, and extra credits.
• Support browser sign-in, API-key entry, and explicit read-only CLI import.

Validation

• just check, cargo fmt --all -- --check, and cargo test --locked — 840 passed.
• Local redirect/callback tests, the offline-proxy check, and read-only live usage smoke test passed.
• Browser sign-in manually verified in the rebuilt Flatpak.

--- Verified SS ----

[rinaldo-rex]

And thanks for the amazing applet! Been using it extensively. Sharing my contribution as a note of thanks! :)