feat: allow list views to use buckets as collapsible sections

[tink-bot]

List views can now use the existing bucket infrastructure to render tasks grouped into collapsible vertical sections, reusing the same bucket system that powers kanban views.

Backend: The two places that gated bucket behavior on ViewKindKanban — task-to-bucket assignment on create and default bucket provisioning on view creation — are widened to all views with BucketConfigurationMode = manual. Done-bucket syncing intentionally stays kanban-only since list view sections are organizational grouping, not workflow stages.

Frontend: Bucket configuration options are ungated for list views in the settings UI. The kanban store is renamed to a generic bucket store. ProjectList.vue gains a sectioned rendering mode with collapsible headers, inline title editing, per-section drag-and-drop (including cross-section moves), "load more" pagination, and section CRUD — while preserving the existing flat list behavior when buckets are not configured.

Test plan

• Create a list view, enable manual bucket configuration in view settings
• Verify default buckets are auto-created and tasks appear in sections
• Test collapsing/expanding sections (state should persist across reloads)
• Drag tasks between sections and within sections
• Create, rename, and delete sections
• Verify existing flat list views and kanban views still work as before

[github-actions]

Preview Deployment

Preview deployments for this PR are available at:

URL	Tag	Commit
https://pr-2614.preview.vikunja.dev	ghcr.io/go-vikunja/vikunja:pr-2614	latest
https://sha-20deac2ce1ee11c401bba217c6fcd6b4e79f7839.preview.vikunja.dev	ghcr.io/go-vikunja/vikunja:sha-20deac2ce1ee11c401bba217c6fcd6b4e79f7839	20deac2

The preview environment will start automatically on first visit. Subsequent pushes to this PR will update the pr-2614 image — the preview picks up the new version on restart. The per-commit URLs point to a specific version and will not change.

Run locally with Docker

docker pull ghcr.io/go-vikunja/vikunja:pr-2614
docker run -p 3456:3456 ghcr.io/go-vikunja/vikunja:pr-2614

Last updated for commit 20deac2

[wucherpfennig]

https://community.vikunja.io/t/feature-request-support-grouped-filter-sections-todoist-style/4384/4