feat(feedback): introduce feedback domain with templates, forms, submission and statistics

[McPringle]

User Story

As an event participant,
I want to receive a feedback form after an event,
so that I can share my experience and help organizers improve future events.

As a community owner or organizer,
I want to define and use feedback templates and review collected responses,
so that feedback becomes a structured and useful part of event management.

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Acceptance Criteria

• Feedback Domain

  • A new business domain named Feedback is introduced.
  • All related entities, services, forms, and UI components are created under this domain.

• Feedback Templates

  • Multiple feedback templates can exist as reusable form definitions.
  • Templates include various supported field types:
    • Single-line text input
    • Multi-line text input
    • Option list (single selection)
    • Single checkbox
    • Multi-checkbox selection
    • Dropdown
    • Read-only text block
  • Instance administrators can create templates available to all events.
  • Community owners can create additional templates restricted to their community.

• Assigning Templates to Events

  • When creating an event, an optional feedback template can be selected from available templates.
  • If no template is selected, the event has no feedback form.

• Standard Template

  • Komunumo provides a built-in default template in all supported languages (currently English and German).
  • The default template includes the questions:
    • "Wie hat dir das Event gefallen?" / "How did you like the event?"
    • "Optionaler Kommentar" / "Optional comment"

• Feedback Submission

  • After an event ends, all registered participants receive an email containing a link to the feedback form.
  • A participant can submit feedback only within a configurable time window (default: 24 hours after event end).
  • After the allowed time expires:
    • Participants see an expiration message when opening the form.
    • A notification email is sent to the community owner and organizers with a link to the statistics dashboard.

• Storage

  • All submitted feedback responses are stored in the database.
  • Responses are tied to the event and to the respective feedback template.

• Statistics

  • Community owners and organizers can view aggregated statistics for their event’s feedback.
  • Statistics are displayed in the browser using charts or summarized values.
  • Only authorized users (community owners/organizers) have access to the statistics.

• Access Control

  • Only event participants can submit feedback.
  • Only authorized community owners and organizers can view feedback results.

• Testing

  • Manual testing is performed successfully on both desktop and mobile devices.
  • Full automated test coverage is implemented for all added code.
  • All automated tests pass.