docs: new release notes

docs/abra/upgrade.md

@@ -18,6 +18,35 @@ abra upgrade --rc
 
 ## Migration guides
 
+### `0.6.x-beta` -> `0.7.x-beta`
+
+> **ALERTA, ALERTA**: this is currently only available via the release
+> candidate channel, using `abra upgrade --rc`. There has been a lot of churn
+> and we're being cautious about releasing this one. Please help us test! We're
+> currently on `0.7.0-rc1-beta`.
+
+- `kadabra`, the app auto-updater is available for general testing! See [these docs](https://docs.coopcloud.tech/operators/tutorial/#automatic-upgrades) for how to get started.
+
+- **ALERTA, ALERTA**, security related issue: all `$domain.env` env vars are now exposed to the deployment via the `app` service container. Each `FOO=BAR` is exported within the context of the container. If you have any privately committed secrets in your `.env` files, please migrate them to the `secrets: ...` configuration in the recipe. This change was made to facilitate tooling which can support auto-upgrading of apps in a deployment.
+
+- `abra` can no longer install Docker, initialise swarm mode and the proxy network. It will check if a Docker install exists and is in swarm mode or not and error out accordingly. We leave the provisioning to tools that are designed for that and reduce the command-line surface that we have to maintain going forward.
+
+- `abra server add <host> <args>` 👉 `abra server add <host>`. We have finally removed the custom SSH handling code and now solely rely on invoke `/usr/bin/ssh` directly and reading from the `~/.ssh/config`. The `<host>` argument should correspond to a `Host <host>` entry in your `~/.ssh/config` or in an `Include <file>` statement (hosts are retrieved via `ssh -G <host>`). This means "how does `abra` interact with SSH is 1) do you have an `~/.ssh/config` entry for `<host>` 2) can you `ssh <host>` successfully? 3) there is no 3. It's an easier mental model and also the way `abra-bash` works, hence, less weird obscure errors. `<host>` being public domain names is still required.
+
+- `abra` no longer tries to do the TOFU host key verification prompt. We follow the praxis of the Docker cli itself and just give up when host keys are not validated. We leave it to folks to ssh in and verify themselves.
+
+- On the way to [`kadabra`](https://git.coopcloud.tech/coop-cloud/abra/pulls/268), several changes regarding labelling deployments have been merged in this release. This will allow tooling to understand a deployment without having the context of a `~/.abra/...` configuration. This will pave the way for server-side tooling, like `kadabra` which can help operators with different kinds of maintenance tasks.
+
+- Welcome `abra recipe fetch`, which helps retrieve a recipe repository to your local work-station.
+
+- Also say hello to `abra app services <domain>`, which lists the in-deployment service names and corresponding image, e.g. `foo_example_com`.
+
+- Digests have been removed from the catalogue generation.
+
+- Backup files generated by `abra` have a much more human-friendly format.
+
+- Linting for domains is disabled when no `DOMAIN=...` is discovered in the `$odmain.env` file.
+
 ### `0.5.x-beta` -> `0.6.x-beta`
 
 - Using `{{ .Domain }}` in recipe `.envrc.sample` files went away because it