Add a Notes/Description Field for Stacks and Containers

[heyvoon]

Is your feature request related to a problem? Please describe

Yes. When managing a large number of stacks and containers, it can be difficult to remember the specific purpose, configuration details, or context for each one. For example:

• Why was a specific environment variable set to a certain value?
• What is the function of this specific stack in a multi-stack application?
• What was the reason for adding a specific volume mount or network?
• Important warnings or instructions for other team members.

This information is often stored externally in wikis, documentation, or README files, leading to context switching and information getting out of sync.

Describe the solution you'd like

I would like a dedicated, editable notes field for both Stacks and individual Containers within the Portainer UI.

• For Stacks: The notes could be a new tab within the stack details view, right next to the existing "Containers", "Services", and "Logs" tabs. Alternatively, it could be a prominent card on the stack overview page.
• For Containers: The notes could be a field within the "Duplicate/Edit" container form and also visible on the container's details page, perhaps in a "Notes" section under the "Overview" tab.

The field should support basic text formatting (like Markdown) for readability and allow for multi-line entries. This would serve as a built-in knowledge base directly linked to the deployed resources.

Describe alternatives you've considered

• Using labels: We currently add comments as labels (e.g., com.portainer.description="This container handles..."). This is a clunky workaround as labels are not designed for long-form text and are difficult to read and edit.
• External Documentation: Maintaining a separate wiki or document. This often becomes outdated quickly and requires users to leave the Portainer interface to get crucial context.
• Naming Conventions: Trying to put all relevant information into the stack/container name, which is not practical for anything beyond very simple details.

Additional context

This feature would significantly improve the maintainability and collaborative management of environments, especially in team settings. It keeps critical context directly attached to the resource it describes.