feat: FORMS-943 Enable File Uploads for Public Forms

[revanth-banala]

Description

Public (anonymous) users were unable to upload files to forms that allow public access. The existing hasFileCreate middleware was blocking all file uploads for users without authentication, even when the form was configured to accept public submissions.

Solution
Updated the hasFileCreate middleware in /src/forms/file/middleware/filePermissions.js to properly handle public form access by:

Allowing authenticated users - Users with idpUserId can upload files to any form (existing behavior)
Checking form configuration for public users - For non-authenticated users, validate that:

Form exists and is active
Form has public identity provider configured

Consistent permission logic - Uses the same identity provider checking pattern as other middleware in the codebase
Maintained existing security for authenticated users

Security Considerations
authenticated users maintain same access
Public forms still require explicit public identity provider configuration
Form must be active for any file uploads

Type of Change

feat (a new feature)

Checklist

• I have read the CONTRIBUTING doc
• I have checked that unit tests pass locally with my changes
• I have run the npm script lint on the frontend and backend
• I have added tests that prove my fix is effective or that my feature works
• I have added necessary documentation (if appropriate)
• I have approval from the product owner for the contribution in this pull request

Further comments

[github-actions]

Release 4ad974a deployed at https://chefs-dev.apps.silver.devops.gov.bc.ca/pr-1696

[usingtechnology]

This looks really good @revanth-banala.
The functionality checks out and was able to upload on public form (while not allowing the download after submitted).
Nice work.

[nimya-aot]

@revanth-banala When we try to download the uploaded file after submitting the form, it throws an error. Can you check that? Is it possible to block download or show a proper message?

[abhilash-aot]

Changes for Public file Upload looks good

[sonarqubecloud]

Quality Gate passed

Issues
0 New issues
0 Accepted issues

Measures
0 Security Hotspots
0.0% Coverage on New Code
0.0% Duplication on New Code

See analysis details on SonarQube Cloud