chore: import upstream snapshot with attribution

docs/tutorials/container-system-config-tutorial.md

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+# Customize `container` default configuration values
+
+> [!IMPORTANT]
+> This file contains documentation for the CURRENT BRANCH. To find documentation for official releases, find the target release on the [Release Page](https://github.com/apple/container/releases) and click the tag corresponding to your release version.
+>
+> Example: [release 0.4.1 tag](https://github.com/apple/container/tree/0.4.1)
+
+Take a guided tour of setting configurations for `container` CLI commands and services.
+
+## Configuration sources
+
+The `container` service loads values from these TOML files at startup, with first-match-wins precedence:
+
+1. Your user file at `~/.config/container/config.toml`.
+2. An optional file shipped with the `container` package install at `<installRoot>/etc/container/config.toml`.
+
+Any key absent from both files falls back to a hardcoded default. For the full schema and defaults, see the [`config.toml` reference](../container-system-config.md).
+
+## Create a custom user TOML configuration file
+
+The `container` service reads your file once at startup, so restart the service whenever you want changes to take effect.
+
+### Open or create your config file
+
+Your editable config lives at `~/.config/container/config.toml`. Create it if it does not exist:
+
+```bash
+mkdir -p ~/.config/container
+touch ~/.config/container/config.toml
+```
+
+### Set the values you want to customize
+
+Open the file in the editor of your choice and add only the sections and keys you want to change. 
+
+For this tutorial, increase the default CPU and memory limits used for each new container and set a DNS domain for resolving container IP addresses from the host. 
+
+```toml
+[container]
+cpus = 8
+memory = "4g"
+
+[dns]
+domain = "test"
+```
+
+Each top-level table maps directly to a section of [ContainerSystemConfig](../container-system-config.md). 
+
+### Restart the `container` service
+
+To make your edits take effect, stop and start the system:
+
+```bash
+container system stop
+container system start
+```
+
+### Verify the values are loaded
+
+Use `container system property list` (alias `ls`) to print the merged configuration that the `container` service is using. 
+
+```console
+% container system property list
+[build]
+cpus = 2
+memory = "2048mb"
+rosetta = true
+image = "ghcr.io/apple/container-builder-shim/builder:0.11.0"
+
+[container]
+cpus = 8
+memory = "4gb"
+
+[dns]
+domain = "test"
+
+[kernel]
+binaryPath = "opt/kata/share/kata-containers/vmlinux-6.18.15-186"
+url = "https://github.com/kata-containers/kata-containers/releases/download/3.28.0/kata-static-3.28.0-arm64.tar.zst"
+
+[network]
+
+[registry]
+domain = "docker.io"
+
+[vminit]
+image = "ghcr.io/apple/containerization/vminit:0.34.0"
+```
+
+For machine-readable output, pass `--format json`:
+
+```bash
+container system property list --format json
+```