feat: example manifests and service files

- examples/minimal.toml — bare openSUSE system
- examples/dev.toml — developer tools (git, vim, tmux, gcc, clang)
- examples/gui-dev.toml — GUI development with GPU + audio passthrough
- examples/ubuntu-dev.toml — Ubuntu-based with Node.js, Python, build-essential
- examples/rust-dev.toml — Rust development environment
- data/dbus/org.karapace.Manager1.service — D-Bus service activation file
- data/systemd/karapace-dbus.service — hardened systemd user unit

data/dbus/org.karapace.Manager1.service

@@ -0,0 +1,4 @@
+[D-BUS Service]
+Name=org.karapace.Manager1
+Exec=/usr/bin/karapace-dbus
+SystemdService=karapace-dbus.service

data/systemd/karapace-dbus.service

@@ -0,0 +1,22 @@
+[Unit]
+Description=Karapace Environment Manager D-Bus Service
+Documentation=https://github.com/karapace/karapace
+
+[Service]
+Type=dbus
+BusName=org.karapace.Manager1
+ExecStart=/usr/bin/karapace-dbus
+# The service implements a 30s idle timeout internally;
+# systemd will restart it on the next D-Bus activation.
+TimeoutStopSec=5
+Restart=on-failure
+RestartSec=2
+# Security hardening
+ProtectSystem=strict
+ProtectHome=read-only
+ReadWritePaths=%h/.local/share/karapace
+PrivateTmp=true
+NoNewPrivileges=true
+
+[Install]
+WantedBy=default.target

examples/dev.toml

@@ -0,0 +1,20 @@
+# Developer environment — common CLI tools for software development.
+# Includes Git, build tools, and editors. No GUI.
+#
+# Usage:
+#   karapace build examples/dev.toml
+#   karapace enter <env_id>
+
+manifest_version = 1
+
+[base]
+image = "rolling"    # openSUSE Tumbleweed
+
+[system]
+packages = ["git", "curl", "vim", "neovim", "tmux", "htop", "make", "cmake", "gcc", "clang"]
+
+[mounts]
+workspace = "~/projects:/workspace"
+
+[runtime]
+backend = "namespace"

examples/gui-dev.toml

@@ -0,0 +1,28 @@
+# GUI development environment — desktop app development with full host integration.
+# Includes GPU, audio, Wayland/X11 passthrough, and common GUI libraries.
+#
+# Usage:
+#   karapace build examples/gui-dev.toml
+#   karapace enter <env_id>
+#   karapace export-app <env_id> my-app /usr/bin/my-app
+
+manifest_version = 1
+
+[base]
+image = "rolling"    # openSUSE Tumbleweed
+
+[system]
+packages = ["git", "curl", "cmake", "gcc", "clang", "gdb", "mesa-dri-devel"]
+
+[gui]
+apps = ["firefox"]
+
+[hardware]
+gpu = true
+audio = true
+
+[mounts]
+workspace = "~/projects:/workspace"
+
+[runtime]
+backend = "namespace"

examples/minimal.toml

@@ -0,0 +1,14 @@
+# Minimal Karapace environment — just a base system, no extras.
+# Good for testing or as a starting point.
+#
+# Usage:
+#   karapace build examples/minimal.toml
+#   karapace enter <env_id>
+
+manifest_version = 1
+
+[base]
+image = "rolling"    # openSUSE Tumbleweed
+
+[runtime]
+backend = "namespace"

examples/rust-dev.toml

@@ -0,0 +1,20 @@
+# Rust development environment — ready for Rust/Cargo development.
+#
+# Usage:
+#   karapace build examples/rust-dev.toml
+#   karapace enter <env_id>
+#   # Then inside: curl --proto '=https' --tlsv1.2 -sSf https://sh.rustup.rs | sh
+
+manifest_version = 1
+
+[base]
+image = "rolling"    # openSUSE Tumbleweed
+
+[system]
+packages = ["git", "curl", "gcc", "make", "cmake", "pkg-config", "openssl-devel", "gdb"]
+
+[mounts]
+workspace = "~/projects:/workspace"
+
+[runtime]
+backend = "namespace"

examples/ubuntu-dev.toml

@@ -0,0 +1,19 @@
+# Ubuntu-based developer environment — for teams requiring Ubuntu toolchains.
+#
+# Usage:
+#   karapace build examples/ubuntu-dev.toml
+#   karapace enter <env_id>
+
+manifest_version = 1
+
+[base]
+image = "ubuntu/24.04"    # Ubuntu Noble Numbat
+
+[system]
+packages = ["git", "curl", "build-essential", "cmake", "python3", "python3-pip", "nodejs", "npm"]
+
+[mounts]
+workspace = "~/projects:/workspace"
+
+[runtime]
+backend = "namespace"