Is your feature request related to a problem?
Currently, Decidim allows sharing content through links, but there is no built-in way to generate and share a QR code. This feature would enhance accessibility and ease of sharing, especially in physical spaces or public events where scanning a QR code is more convenient than typing a URL.

Describe the solution you'd like

As a visitor, when I click on the "Share" action, I want to see a new option to share via QR code.

• When selecting this option, a modal window appears displaying the generated QR code corresponding to the content’s URL.
• The modal includes two buttons (see Figma file):
  • Download – allows saving the QR as an image file.
  • Print Poster – opens a print-friendly page featuring the QR code along with relevant metadata (the title of the content, the placeholder image and the organization logo).

Mock-ups / Prototype
https://www.figma.com/design/1oiYPbgbpYCXDlizz9bSxs/Internal-Decidim?node-id=1255-52732&t=6G3ojuwXOlDLWA2w-4

Describe alternatives you've considered
An alternative would be using external QR code generators, but integrating this functionality directly into Decidim simplifies the process and ensures consistency in presentation.

Additional context*
https://meta.decidim.org/processes/roadmap/f/122/proposals/17234

Does this issue impact users' private data?
No.

Acceptance Criteria

• Given I am a visitor, when I click on the "Share" button, then I see an option to share via QR code.
• Given I select the "QR Code" option, then a modal appears displaying the QR code linked to the content’s URL.
• Given I see the QR code modal, when I click on the "Download" button, then the QR code is downloaded as an image file.
• Given I see the QR code modal, when I click on the "Print Poster" button, then a print-friendly page opens with the QR code and content details.