Share env variables with services a-la Railway

What problem will this feature address?

First, I’ve moved my 8 year old app from Railway —> Dokploy a few weeks ago and I’m generally very happy with this decision. Big thanks to maintainers.

One thing I sorely miss is Railway’s approach to environment variables. I’ll describe it in the next section.

The (first-world) problem: especially in monorepos where the same image can drive different apps (think web, workers sharing the same codebase) that often need the same env vars, verifying a new variable has made it to all those apps (in my case, 5) is tedious and error-prone. The fact we can define it per env and reference it in the apps is great, but I think it can be made even nicer.

Describe the solution you'd like

Allow the user to declare env-scoped variables (already exists) and share them with apps from Dokploy’s UI. Also allow “promoting” an app-scoped variable to a shared variable seamlessly, and share it with any number of existing apps in the environment.

Big bonus: the ability to specify that a change to environment variables should trigger a deployment.

Describe alternatives you've considered

Staying with the current setup. I don’t know of any other alternatives.

Additional context

No response

Will you send a PR to implement it?

Maybe, need help

No files or tests are named. Start by tracing the existing environment-variable flows for environments and apps in the Dokploy UI, then determine how shared variables and promotion should interact with existing apps. Done should include sharing one environment-scoped variable with multiple apps, promoting an app-scoped variable, and clarifying whether variable changes trigger deployments.