Create permanent links to published files or images

Is your feature request related to a problem? Please describe.
Currently, some links and multimedia files, such as images, hosted on Decidim become inaccessible over time, either due to server expiry policies, automatic temporary file clean-ups, or infrastructure changes. This causes continuity issues and loss of information, especially in participatory processes that need to maintain documentary traceability over the years.

Describe the solution you'd like
The improvement would be to ensure that all links and images uploaded to the platform remain permanently available, to guarantee:

• The preservation of the historical record of the processes.

• Future transparency and auditability.

• Content stability, avoiding visual or documentary breaks.

• A better user experience and greater trust in the platform.

Describe alternatives you've considered
If maintaining the links over time is not viable, we could keep them active for a longer period of time.

Additional context-Add any other context or screenshots about the feature request here.

Does this issue could impact on users private data?
The visibility of files published in private participation spaces must be taken into account.