feat: Add open-webui example using Docker

- Created an example to create a docker image for open-webui
- The `docker_recipe_env.v` file is updated to correctly handle quoting in environment variables.

Co-authored-by: mahmmoud.hassanein <mahmmoud.hassanein@gmail.com>

examples/virt/docker/ai_web_ui/ai_web_ui.vsh

@@ -0,0 +1,30 @@
+#!/usr/bin/env -S v -n -w -gc none  -cc tcc -d use_openssl -enable-globals run
+
+import freeflowuniverse.herolib.virt.docker
+
+mut engine := docker.new(prefix: '', localonly: true)!
+
+mut r := engine.recipe_new(name: 'dev_ubuntu', platform: .ubuntu)
+
+r.add_from(image: 'ubuntu', tag: 'latest')!
+r.add_package(name: 'git,curl')!
+
+r.add_zinit()!
+r.add_sshserver()!
+
+r.add_run(cmd: 'curl -LsSf https://astral.sh/uv/install.sh | sh')!
+r.add_env('PATH', '/root/.local/bin:\$PATH')!
+r.add_run(cmd: 'uv python install 3.12')!
+r.add_run(cmd: 'uv venv /opt/venv')!
+r.add_env('VIRTUAL_ENV', '/opt/venv')!
+r.add_env('PATH', '/opt/venv/bin:\$PATH')!
+r.add_run(cmd: 'uv pip install open-webui')!
+r.add_zinit_cmd(
+	exec: "bash -c 'VIRTUAL_ENV=/opt/venv DATA_DIR=~/.open-webui /root/.local/bin/uvx --python 3.12 open-webui serve'"
+	name: 'open-webui'
+)!
+
+r.add_run(cmd: 'apt-get clean')!
+r.add_run(cmd: 'rm -rf /var/lib/apt/lists/*')!
+
+r.build(true)!

lib/virt/docker/docker_recipe_env.v

@@ -25,5 +25,5 @@ pub fn (mut i EnvItem) check() ! {
 }
 
 pub fn (mut i EnvItem) render() !string {
-	return "ENV ${i.name}='${i.value}'"
+	return 'ENV ${i.name}="${i.value}"'
 }