Optional archive storage for maps

[cbix]

Describe the idea

It has been pointed out in issues like #13943 or these docs that loading maps from internal storage can be significantly faster than from external storage like SD cards or USB drives. Those however usually provide more space, so one idea to improve the situation would be an optional archive storage location setting for rarely used maps.

The user could define an archive storage and for individual maps select where they're stored (main or archive) and easily move maps between the two (e.g. before a trip to that region). This would save bandwidth (no re-download of maps) and loading time (the active map is on internal storage).

Expected behaviour

Under Maps & Resources:

• allow moving a map to archive
• if the archive storage is available (SD/USB plugged in), scan for available maps and allow moving them to main storage

When viewing maps:

• only regions on main storage are visible
• when selecting a region that is not downloaded: show "download region" button (this is the current behavior)
• when selecting a region that is downloaded but archived: show "activate region" button to move the map to main storage

Alternatives you've considered

As explained in the docs the existing solutions are:

1. only using internal storage (fast but limited capacity)
2. only using external storage (large capacity but slow)
3. manually moving map files between external/internal storage on demand (tedious process, involves using a file browser app and remembering where files are stored)
4. deleting unused maps and downloading them on demand (requires internet connection and uses up bandwidth)

The proposed solution would basically make option 3 much simpler and accessible from within the app.

Context

Related issues:

• Use "Storage Access Framework" to allow storing maps on external sdcard #7045
• Slow Map Loading on SDcard #13943

[yuriiurshuliak]

This request offers an optional archive storage feature for rarely used maps. This would allow users to move maps between internal (fast) and external (large but slow) storage within the app, improving convenience and performance without requiring manual file management or redownloading maps.