add the installer, and document the 2.0 CLI

install.sh handles a system or a user prefix, clones the catalogue on demand
and writes the machine config in the right place for the distribution.

CHANGELOG.md

@@ -1,5 +1,17 @@
 # CHANGELOG
 
+## v2.0.0-dev - 2026-09-03
+
+- new bash CLI (`bin/myos`, `lib/`): one model for a project directory, a
+  catalogue stack, a group and a host singleton
+- unknown command or unknown stack now fails, instead of succeeding silently
+- default compose project is `<user>-<env>-<app>`; set
+  `MYOS_PROJECT_FORMAT=user-app-env` on deployments created before this
+- `myos ls`, `myos env`, `myos doctor` to inspect an installation
+- `install.sh`, and the catalogue is looked up beside the installation
+- agent skill in `skills/myos/`, contributor notes in `AGENTS.md`
+- the make engine still works and is still covered by the golden tests
+
 ## v1.1 - 2026-09-03
 
 - move the stack catalogue and the docker build contexts to the myos-stacks project

README.md

@@ -61,6 +61,9 @@ sudo git clone https://github.com/aya/myos-stacks /usr/local/share/myos
 ## Usage
 
 ```sh
+myos doctor                      # check the installation first
+myos ls                          # what stacks are reachable
+myos -n up host                  # print what it would run
 myos up                          # the stack of the current directory
 myos up STACK=host               # a group of stacks, see stack/host/host.mk
 myos up STACK=host/fabio         # a single stack
@@ -108,16 +111,25 @@ Networks: `default` = `_<project>` (private to the project), `private` =
 | `ENV=<env>` | environment: selects `.env.<env>` and the `<name>.<env>.yml` overlays |
 | `STACK=<refs>` | stacks to act on |
 | `SERVICE=<name>` | target one compose service (`exec`, `run`, `logs`, `scale`) |
+| `MYOS_PROJECT_FORMAT` | `user-env-app` (default) or `user-app-env` for deployments made before myos 2.0 |
 
 ```sh
-myos print-COMPOSE_FILE           # show a variable
-myos print-COMPOSE_PROJECT_NAME
-myos debug                        # show debug variables
-myos doc                          # self documentation from the make comments
+myos env COMPOSE_FILE             # show a variable
+myos env COMPOSE_PROJECT_NAME
+myos config <stack>               # the rendered compose file
 ```
 
+The make targets keep working: `print-VAR`, `stack-<stack>-<command>`,
+`<command>@<env>`, and a project `Makefile` that includes `make/include.mk`.
+
 `SETUP_UFW=true` enables the ufw/ufw-docker integration (`myos setup-ufw`).
 
+## For agents
+
+`skills/myos/SKILL.md` is a skill describing how to drive myos, with
+references on the conventions, the commands and the failure modes.
+`AGENTS.md` covers changing myos itself.
+
 ## Tests
 
 ```sh