music: group playback commands under /music

Graduate grajcuj/skip/queue/stop/join into the /music parent and drop the
top-level names. On startup, reconcile global slash commands and delete
any that are no longer registered, since Discord otherwise keeps stale
commands after a rename or move.

Docs updated for the new command layout and queue semantics.

1 files changed, 11 insertions, 1 deletions

diff --git a/CONTEXT.md b/CONTEXT.md
index 990dc8e..278420f 100644
--- a/CONTEXT.md
+++ b/CONTEXT.md
@@ -50,7 +50,17 @@ holds no implementation decisions or specs (those live in `docs/adr/`).
 
 ## Music Playback
 
-- **Compressed playback** — `/grajcuj \w compressed`: downloads audio, runs
+- **Queue** — per-guild, in-memory list of tracks waiting to play. Lost on
+  restart. `/music queue` shows the current track first, then the pending
+  items in play order.
+- **Position** — where `/music grajcuj` inserts a track: `now` interrupts the
+  current track, `next` inserts after it, `last` appends (default). When
+  nothing is playing, every position starts playback immediately.
+- **Skip** — stop the current track and play the next queued one. With an
+  empty queue, playback stops but the bot stays in the voice channel.
+- **Auto-advance** — when a track ends (or errors), the next queued track is
+  started automatically and announced in the channel.
+- **Compressed playback** — `/music grajcuj ... compressed`: downloads audio, runs
   through the /compress pipeline (Opus 500bps, 12 kHz, mono → OGG), then
   decodes the compressed file via symphonia for playback. Produces properly
   destroyed audio via Opus codec, not just raw low-sample-rate PCM.