[AGILE-436] Document batch selection in Lookbook

[myabc]

Ticket

https://community.openproject.org/wp/AGILE-436

What are you trying to accomplish?

Bring the Lookbook sortable-list guide and API reference up to date with batch selection, movement and action menus. This documentation was added after AGILE-392's approved scope and is now submitted separately for review.

What approach did you choose and why?

Documents gestures, range sessions, mobility, destination intersection, collection requests and menu scopes. Updates the selection style guide and removes obsolete preview attributes. The README retains implementation ownership and invariants and links to the consumer guide.

Depends on AGILE-362, AGILE-363 and AGILE-364; this PR is based on AGILE-364. AGILE-392 (#24858) is independent and targets dev.

The documentation patch is unchanged from the extracted commit c05cfa5. No runtime behavior changes.

Validation

• Exact documentation patch preserved during extraction; git whitespace checks pass.
• This remains a draft for a separate documentation review and rendered Lookbook QA.

[Copilot]

🟡 Changes recommended

Clarify the documented batch-size, item-type, and selection-state behavior before approval.

Get a fresh assessment by requesting another Copilot review.

Pull request overview

Updates sortable-list documentation for batch selection, movement, accessibility states, and action menus. No runtime behavior changes.

Changes:

• Documents batch gestures, mobility, movement, and destination actions.
• Expands API and collection-move guidance.
• Removes obsolete preview targets and updates README links.

File summaries

File	Summary
lookbook/previews/patterns/sortable_lists_preview/single_list.html.erb	Removes obsolete divider target.
lookbook/previews/patterns/sortable_lists_preview/sibling_lists.html.erb	Removes obsolete divider target.
lookbook/docs/40-styles/10-box-list-item-states.md.erb	Documents selection and current-item states.
lookbook/docs/20-patterns/46-drag-and-drop[api-reference].md.erb	Documents batch-selection APIs and collection moves.
lookbook/docs/20-patterns/44-drag-and-drop[sibling-lists].md.erb	Documents batch gestures and movement.
lookbook/docs/20-patterns/43-drag-and-drop[one-list].md.erb	Updates action-menu guidance.
lookbook/docs/20-patterns/42-drag-and-drop[implementation-overview].md.erb	Updates sortable-list implementation terminology.
frontend/src/stimulus/controllers/dynamic/sortable-lists/README.md	Links implementation guidance to Lookbook.

Review details

Suppressed comments (2)

lookbook/docs/20-patterns/44-drag-and-drop[sibling-lists].md.erb:134

• The orchestrator enforces one item type per batch: toggling an item of another type restarts the batch, and collection moves submit bare IDs to one endpoint. This consumer guide says Ctrl/Cmd-click can build a sparse batch across lists without stating that invariant, which makes cross-type batches appear supported.

Ctrl/Cmd-click toggles individual items and can build a sparse batch across
lists. The toggled item becomes the anchor even when deselected. Plain click
replaces the selection with the movable item while allowing its activation.

lookbook/docs/40-styles/10-box-list-item-states.md.erb:19

• This wording conflicts with the selection behavior documented immediately above and implemented by the controller: a plain click on another movable card both opens its details and replaces/collapses the current batch. Please distinguish the details-pane current state from the activation gesture, which can change batch membership.

An item can carry both states simultaneously when it is selected *and* currently shown in the detail panel. Keyboard focus is independent of both states. Opening another work package in the details pane does not change batch membership.

• Files reviewed: 8/8 changed files
• Comments generated: 2
• Review effort level: Lite

---

💡 Add a code-review agent skill or configure MCP servers for context-aware, tailored reviews. Learn more in the docs.