Docs: say plainly that only the bot is open source; the dashboard and API are proprietary

- README, license section and architecture no longer point to the dashboard repositories
- schema.sql is the schema for contributors; database changes only need schema.sql and a note in the PR
- self-hosting: settings without a dashboard (SQL for security thresholds, beta settings, opted-in servers)
- beta features, deployment and troubleshooting reworded for people who don't have the dashboard

Co-Authored-By: Claude Sonnet 5.5 <[email protected]>

docs/features.md

@@ -29,7 +29,7 @@ Rules that hold everywhere in this module:
 - Roles that are configured (such as the quarantine role) are checked when they are used, not only when saved. A quarantine role that gained dangerous permissions is not assigned.
 - Messages ping only the configured alert role, and names are escaped.
 
-Thresholds, Join Gate filters and heat settings are set on the dashboard. The bot's role must be above the roles it protects against: it can only quarantine members whose highest role is below its own.
+Thresholds, Join Gate filters and heat settings are rows in the `security_settings` table (the hosted Velox edits them on its dashboard; see [Settings without a dashboard](self-hosting.md#settings-without-a-dashboard)). The bot's role must be above the roles it protects against: it can only quarantine members whose highest role is below its own.
 
 ## Tickets
 
@@ -69,7 +69,7 @@ Lavalink-powered playback. Code: `internal/music`, commands in `internal/command
 - `/play` takes a name or a URL, `/queue` shows the queue, `/volume` sets 0 to 150 percent. These need a role called **DJ**.
 - The now-playing message has buttons for playback and repeat. Buttons also check for the DJ role.
 - `/music toggle` (Manage Server) turns music on or off in a server.
-- The dashboard shows the queue and can control playback. It does so through the `music_commands` table and a `NOTIFY` (see [Database](database.md)).
+- The queue and now-playing state are kept in the database, and playback can be controlled by writing to the `music_commands` table. The hosted Velox dashboard uses this (see [Database](database.md)).
 - Music needs a Lavalink server. Without `LAVALINK_HOST` the rest of the bot works and music does not.
 
 ## Meeting rooms