0020. Library paths relative to the library folders

• Status: Accepted
• Date: 2026-10-18

Context

The library stored each comic's absolute path. The database can live in a synced or shared folder (ADR 0003), and the comics on a network share or a cloud drive are not mounted at the same path on every computer, so a library only worked on the machine that built it.

Decision

A comic inside a library folder (a scanned folder or the organized one) is stored as root:<folder id>/<relative path>; the folder id is in the database, the folder's path on each computer is in a local file (library-roots.json, PathRoots). Comics outside every folder keep their absolute path. Only LibraryRepository sees the stored form. A folder with no path on this computer is listed in Paramètres › Bibliothèque to be located.

Consequences

• The library opens wherever the folders are mounted, after locating each folder once per computer.
• Forgetting a folder only unwatches it, since stored paths refer to it; moving the organized folder in the settings registers a new root.
• The JSON export still names comics by absolute path.
• Comics added on their own, outside any folder, are still tied to their path.

Alternatives considered

• One column of relative paths against a single library root: breaks as soon as comics come from several folders or from single files.
• Folder paths in the database: shared between machines, so every computer would overwrite the others' paths.