[BACKEND] URL-encode task pagination links when filters are present

[utksh1]

Problem

list_tasks() builds pagination.next and pagination.previous by manually concatenating query strings. Filter values such as plugin_id and status are not URL-encoded.

Expected behavior

Pagination links should be generated with urllib.parse.urlencode() or an equivalent structured API.

Acceptance criteria

• Replace manual query string concatenation in task pagination links.
• Preserve existing pagination response fields.
• Add a backend test covering filtered pagination with characters that require encoding.

[saurabhhhcodes]

Hi @utksh1, I would like to work on this under GSSoC 2026.\n\nPlan:\n- replace the manual pagination.next / pagination.previous query-string construction in list_tasks() with urllib.parse.urlencode() or a structured equivalent\n- preserve the existing response shape and pagination fields\n- add a focused backend test where filtered pagination includes characters that require percent-encoding\n\nI checked for open PR overlap: #334 is a broader cursor-pagination PR for #220 and does not appear to target this specific task pagination encoding bug. I will keep this PR scoped to #466.

[HitanshiThakar]

Hi @utksh1, I’d like to work on this issue under GSSoC'26.
I recently contributed to this project, so I’m already familiar with the backend structure and test setup. Planning to replace the manual query string construction with structured URL encoding and add a pagination test covering encoded filter values/special characters.
Kindly assign it to me.