Add individual track download (closes #100)

[Mounstroya]

Allows users to download single songs for offline playback.

Changes:

• Long-press any track → more options sheet now shows Download/Remove Download
• Now Playing screen shows a download button next to the ♥ icon
• Download status indicator (downloaded icon) already worked per-song via useDownloadStatus('song', id) — no changes needed in TrackRow/SongRow

Implementation:

• New enqueueSongDownload(song) in musicCacheService — stores the track under its own ID as itemId
• DownloadButton extended to accept type: 'song'
• MoreOptionsSheet canDownload() now includes songs

Closes #100

[Mounstroya]

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Re: CI translation failure

The translation validation errors (activeShares, logging, serverAccount, etc.) are pre-existing in the master branch and are not related to this PR.

My branch makes zero changes to any src/i18n/ file — you can verify with:

git diff master -- src/i18n/

These keys exist in en.json on master but are missing from the other locale files. The CI would fail the same way on a fresh checkout of master.

[ghenry22]

Yeh just ignore the translation thing, I have pushed a rule update that just warns rather than bombing CI on translation gaps.

Thanks for the PR, I will review this but I need to also implement song based browsing otherwise there is not a good way to actually browse and play the offline songs.

Song browsing and downloading is towards the top of my todo list, I have an update with a bunch of stability work and fixes in it to go out shortly then this will be worked on for the next update after that.

I am trying to push updates out roughly once a week so I don't burn all my CI credit!

[Mounstroya]

Hey! Thanks for the update, the recent changes look great.

I was wondering if you have a place where you track upcoming features or things you're currently working on? I'd really love to contribute more, and it would help me focus on areas that are actually useful for the project 🙂

I was quite excited about my previous contribution 😿 , so I'd love to keep helping

[ghenry22]

Hey! Thanks for the update, the recent changes look great.

I was wondering if you have a place where you track upcoming features or things you're currently working on? I'd really love to contribute more, and it would help me focus on areas that are actually useful for the project 🙂

I was quite excited about my previous contribution 😿 , so I'd love to keep helping

Thanks for taking the time and effort to make a PR for this. I already had a plan and work underway for how I wanted to handle surfacing individual songs in the library list and as downloads. This work has all been completed and is now in github, it will roll out in the next release.

For a list of features it is generally what is logged on github and then things from my own testing that roll in as well. I do have a specific way that I want to handle somethings (particularly bigger features like carplay/android auto, gapless playback etc).

While I might not merge every PR they are still extremely useful as a reference when I do implement the functionality and I certainly appreciate the community contributions!