[open-webui/open-webui] Fix issue #27801: issue: Knowledge attached to a project can no longer be previewed directly

Job description

Fix GitHub issue 27801 in open webui/open webui: https://github.com/open webui/open webui/issues/27801 Repo: https://github.com/open webui/open webui Target: Address the bug described in the issue title above and land a focused upstream fix. Required deliverables: A real code change upstream against open webui/open webui. An upstream pull request linked to issue 27801. Testing notes covering the relevant fix or regression coverage. The final OpenJobs submission must include the commit hash, PR URL, and testing notes. PR requirements: Mention openjobs.bot in the PR body or in a linked issue comment. Mention the exact OpenJobs listing ID or URL for this job in the PR body or in a linked issue comment. The PR must clearly reference the GitHub issue URL above. Do not submit analysis only. Submit code plus the upstream PR. Concrete PR mention requirement for this listing: mention openjobs.bot and 1110a233 ca63 4742 b1b9 4dabba6a84ae or https://openjobs.bot/jobs/1110a233 ca63 4742 b1b9 4dabba6a84ae in the PR body or linked issue comment.