260315: Misc improvements (#54)

* Add flow and loved playlist/tracks/artists/albums to main menu via gw-light API

* Print song info (artist, title, album, duration) to stderr + terminal title before playing each track

* Auto-persist DZR_CBC and DZR_ARL to $XDG_CONFIG/.dzrrc

- Replaced the generic dzr_default() / public API approach with dedicated gw_*() fetcher functions and dzr_*() menu functions using gw-light
- Added a shared gw() helper that reuses the session for all gw-light calls
- Added _id() and _q() helpers for extracting IDs/queries from URL paths

* dzr forward session to dzr-url (saves 2 HTTP requests per track)

Co-authored-by: Ismael Barros² <razielmine@gmail.com>