Backport from the iOS version: offline downloads, home-first reconnect, stall warning, Close

- Downloads for offline listening: long-press a track, album, artist or
  playlist -> Download; Menu -> Downloads lists them (progress, space used/free,
  play/shuffle, retry, remove). Saved on the SD card (Android/data/com.minamp/
  files/downloads). MP3 originals kept as they are unless above a lower
  download quality; the rest transcoded to MP3 (320 kbps by default). One at a
  time, Range resume for originals, retried when the server is back, Wi-Fi lock.
- Downloaded tracks play from the SD card, offline too; plays made offline
  are reported to Plex when a connection works again.
- Server.pick: when last time's connection was remote, give the plain home
  addresses 2 s first (a hairpinned remote address kept us encrypted and
  capped at home). test/PreferHomeTest.java.
- Playback "playing" but not moving for 12 s: say so instead of staying silent.
- Menu -> Close Minamp: stop the music and close every screen.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

res/values-en/strings.xml

@@ -7,6 +7,7 @@
     <string name="address_hint">Address</string>
     <string name="album">Album</string>
     <string name="album_link">Album ›</string>
+    <string name="already_downloaded">Already downloaded</string>
     <string name="app_name">Minamp</string>
     <string name="applies_next_track">Applies from the next track</string>
     <string name="artist">Artist</string>
@@ -15,6 +16,7 @@
     <string name="back">Back</string>
     <string name="buffering">Buffering…</string>
     <string name="cancel">Cancel</string>
+    <string name="cancel_downloads">Cancel pending downloads</string>
     <string name="cant_list_servers">Couldn\'t list servers: %1$s</string>
     <string name="cant_load_tap">Couldn\'t load: %1$s  (tap to retry)</string>
     <string name="cant_reach_plextv">Couldn\'t reach plex.tv: %1$s</string>
@@ -34,8 +36,25 @@
     <string name="contacting_plextv">Contacting plex.tv…\n(the first secure connection takes a few seconds on this phone)</string>
     <string name="decade_radio_x">%1$ds radio</string>
     <string name="decade_x">%1$ds</string>
+    <string name="delete_all_confirm">Delete every downloaded track from this phone?</string>
+    <string name="delete_all_downloads">Delete all downloads</string>
+    <string name="dl_done_section">On this phone</string>
+    <string name="dl_empty">Nothing downloaded yet.\nLong-press an album, playlist or track and choose Download.</string>
+    <string name="dl_failed">Failed: %1$s (tap to retry)</string>
+    <string name="dl_in_progress">In progress</string>
+    <string name="dl_no_space">Not enough free space</string>
+    <string name="dl_progress">Downloading %1$d%%</string>
+    <string name="dl_quality_original">Original MP3s, others 320 kbps</string>
+    <string name="dl_quality_title">Download quality</string>
+    <string name="dl_retrying">Will retry when the server is reachable</string>
+    <string name="dl_summary">%1$d tracks · %2$s · %3$s free</string>
+    <string name="dl_waiting">Waiting</string>
+    <string name="download">Download</string>
     <string name="download_first_toast">Download before playing: %1$s</string>
+    <string name="downloaded">Downloaded</string>
     <string name="downloading_pct">Downloading %1$d%%</string>
+    <string name="downloading_x">Downloading %1$s…</string>
+    <string name="downloads">Downloads</string>
     <string name="end_of_track">End of track</string>
     <string name="enter_address">Enter your server\'s address</string>
     <string name="error_last_time">Minamp hit an error last time</string>
@@ -108,12 +127,15 @@
     <string name="quality_home_title">Quality at home</string>
     <string name="quality_original">Original</string>
     <string name="queue_empty">The queue is empty</string>
+    <string name="queued_n">%1$d tracks added to downloads</string>
+    <string name="quit_app">Close Minamp</string>
     <string name="random_album">Random album</string>
     <string name="random_album_sub">Feeling lucky</string>
     <string name="recently_added">Recently added</string>
     <string name="recently_played">Recently played</string>
     <string name="reconnecting">Reconnecting…</string>
     <string name="refresh">Refresh</string>
+    <string name="remove_download">Remove download</string>
     <string name="remove_from_queue">Remove from queue</string>
     <string name="repeat_off">Repeat off</string>
     <string name="repeat_queue">Repeat queue</string>
@@ -135,6 +157,8 @@
     <string name="server_wants_token">The server wants a token (or sign in with Plex instead)</string>
     <string name="server_yours">Yours</string>
     <string name="set_connection">Connection: %1$s</string>
+    <string name="set_delete_downloads">Delete all downloads (%1$s)</string>
+    <string name="set_dl_quality">Download quality: %1$s</string>
     <string name="set_download_first">Download tracks before playing: %1$s</string>
     <string name="set_language">Language: %1$s</string>
     <string name="set_library">Library: %1$s</string>
@@ -175,6 +199,7 @@
     <string name="sort_played">Most played</string>
     <string name="sort_title">Title</string>
     <string name="sort_year">Year (newest)</string>
+    <string name="stalled">Playback is stuck. Try pausing and playing again.</string>
     <string name="starting_x">Starting %1$s…</string>
     <string name="stream_interrupted">Stream interrupted</string>
     <string name="surprise_me">Surprise me</string>