Get the repo ready for F-Droid

- License: AGPL-3.0-or-later (LICENSE, every package.json, README).
- MUSICSHARE_FOSS=1 builds leave out the only closed-source code, Google's
  ML Kit / Play Services barcode scanner bundled by expo-camera; the scan
  screen then decodes small camera snapshots with jsQR instead.
- Expo modules build from source rather than from precompiled AARs, as
  F-Droid requires (that's also what makes the scanner switch take effect).
  Verified: a FOSS build contains no ML Kit or Play Services classes.
- Release builds default to the production server, and come out unsigned
  without our upload key (F-Droid signs with its own). versionCode 1.
- Store listing in fastlane/metadata/android, a draft fdroiddata recipe in
  fdroid/, and docs/FDROID.md with the submission steps.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01MzFywujuH9TiuXbr9vjoX8

fastlane/metadata/android/en-US/full_description.txt

@@ -0,0 +1,35 @@
+<p>musicshare shows you what your friends are listening to, live, and opens any song in the music app <i>you</i> use. A friend on Spotify is playing something great and you use YouTube Music? One tap and it's playing in YouTube Music.</p>
+
+<p><b>Share what you play</b></p>
+<ul>
+<li><b>Any music app on this phone:</b> Spotify, YouTube Music, Apple Music, TIDAL, Deezer, SoundCloud, Plexamp and more. Turn on "This phone" once and everything you play is shared. No accounts to link.</li>
+<li><b>Last.fm and ListenBrainz</b>, including Spotify's own link to them, so your plays from other devices show up too.</li>
+<li><b>Plex and Jellyfin</b> for your own music servers.</li>
+<li>Pause sharing any time, for an hour, until tomorrow, or until you turn it back on.</li>
+</ul>
+
+<p><b>See your friends</b></p>
+<ul>
+<li>A live feed of what your friends are playing, with where they are in the song.</li>
+<li>Pin your favourite people to the top.</li>
+<li>React to a song with an emoji, and see who reacted to yours.</li>
+<li>Recently played and a featured song on every profile.</li>
+<li>Add friends by username or by scanning their QR code.</li>
+</ul>
+
+<p><b>Open it anywhere</b></p>
+<ul>
+<li>Every song opens in Spotify, Apple Music, YouTube Music, Deezer or TIDAL.</li>
+<li>Share a song with anyone: the link opens a page with buttons for every service.</li>
+</ul>
+
+<p><b>Privacy</b></p>
+<ul>
+<li>No ads, no analytics, no trackers.</li>
+<li>The "This phone" feature uses Android's notification access only to read the song, artist and album from music apps you allow. It never reads your notifications or messages.</li>
+<li>Block and report people, remove followers, and delete your account from the app.</li>
+</ul>
+
+<p>Your profile and what you play are public by design: that's the point of the app. musicshare is free and open source (AGPL-3.0); the server can be self-hosted.</p>
+
+<p><i>musicshare isn't affiliated with Spotify, Apple, Google, Last.fm, ListenBrainz, Plex, Jellyfin, Deezer or TIDAL. Connecting some of these services means using them, which F-Droid marks as "promotes non-free network services".</i></p>