Prepare for open source: Apache-2.0 license, contributing guide, self-hosting guide, fix Close()

- LICENSE (Apache-2.0), NOTICE, CONTRIBUTING.md
- docs/self-hosting.md and README sections for hosting and contributing
- Close() no longer crashes: it only disconnects and leaves the slash commands registered, so they keep their IDs across restarts
- Tests use a neutral server ID

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

README.md

@@ -16,6 +16,7 @@ This README is the front page. The rest of the documentation lives in [`docs/`](
 | Page | What is in it |
 | --- | --- |
 | [Getting started](docs/getting-started.md) | Requirements, creating the Discord application, configuration, database, running locally |
+| [Host your own bot](docs/self-hosting.md) | A step-by-step guide to running your own copy on a server, with Docker Compose |
 | [Deployment](docs/deployment.md) | Docker, Compose, upgrade order, backups |
 | [Architecture](docs/architecture.md) | How the code is laid out, how an interaction flows through it, background loops, the link to the dashboard |
 | [Features](docs/features.md) | What each module does and how it behaves |
@@ -71,6 +72,19 @@ internal/modlog, rankcard   small shared helpers
 schema.sql                  mirror of the tables the bot reads and writes
 ```
 
+## Host your own bot
+
+You can run your own copy under your own Discord application. [Host your own bot](docs/self-hosting.md) walks through it on a fresh server with Docker Compose: creating the application and the invite link, configuring the bot, loading the database, optional music and Twitch, backups and updates.
+
 ## Contributing
 
-Start with the [Development guide](docs/development.md). In short: keep a command's definition and its handler in one package, keep SQL in a repo and rules in a service, and run `go build ./... && go vet ./... && go test ./...` before opening a pull request.
+Contributions are welcome: bug reports, fixes, documentation and new features.
+
+- Read [CONTRIBUTING.md](CONTRIBUTING.md) first. It covers how to report a problem, how to propose a change, and what a good pull request looks like.
+- The [Development guide](docs/development.md) shows how to add a command, a button, an event handler, a setting or a table, and how to test them.
+- For anything big, open an issue to talk about it before you write the code.
+- Pull requests go to the `dev` branch. Before opening one, run `gofmt` on the files you touched and `go build ./... && go vet ./... && go test -race ./...`.
+
+## License
+
+Velox Bot is released under the [Apache License 2.0](LICENSE). Copyright 2026 Fernando Videira. See [NOTICE](NOTICE). The libraries it uses are under their own permissive licenses (see `go.mod`).