- Replace split 'Default Download Path' and 'All Categories Base' with a canonical baseDownloadFolder and categorySubfolders model
- Retain absolute category overrides only where required
- Update Add window to accurately reflect intended destination:
- Single URL: specific category path
- Multiple URLs: base folder with explanatory text
- Manual Browse override: selected folder
- Centralize path resolution logic shared by Rust backend and UI
- Strip password, cookies, and headers from download_queue before writing
to store.bin; secrets remain in-memory for the active session only.
- Move extension pairing token from PersistedSettings to the OS keychain,
rotating it on upgrade from versions that persisted it as plaintext.
- Add ignores_legacy_extension_pairing_token_field test to confirm serde
silently drops the old field so existing installs migrate cleanly.
- Document intentional retention of URLs (signed params are the download
source and cannot be redacted without breaking resume/retry).