Separate Dashboard-tree expansion from opening the Dashboard

[BorisTyshkevich]

Problem

The Dashboard hierarchy currently uses the Dashboard row itself to expand/collapse the tree, while opening the Dashboard in View mode requires a different gesture.

This makes the primary Dashboard name behave like a disclosure control instead of navigation. Users expect the Dashboard name to open that Dashboard, while the visible chevron should own hierarchy expansion.

This revises the Dashboard-row gesture contract originally defined in #426.

Required behaviour

Split the Dashboard row into distinct click targets:

• Disclosure chevron (> / expanded variant): expand or collapse that Dashboard's hierarchy only.
• Dashboard name / primary row content: open the exact Dashboard in View mode on the main surface.
• Trailing action menu: retain its existing Dashboard actions and do not trigger navigation or expansion.

Opening the Dashboard must use its stable Dashboard ID:

openDashboard({ dashboardId, mode: 'view' });

Do not identify the Dashboard by title or collection position.

Interaction details

• Clicking the Dashboard name must not change its expanded/collapsed tree state.
• Clicking the chevron must not open, rerender, or focus the Dashboard surface.
• The Dashboard icon may be part of the same primary navigation target as the name.
• Double-clicking the name must not create duplicate navigation/history entries or introduce a second action.
• If Shift-click currently opens Edit mode, retain that behaviour on the primary name target unless Edit navigation is redesigned separately.
• Menu-button clicks must stop propagation and affect neither expansion nor navigation.

The old delayed single-click/double-click arbitration is no longer needed for Dashboard rows because expansion and navigation have separate explicit targets. Member-row arbitration is outside this issue unless shared code requires a safe refactor.

Keyboard and accessibility

• The chevron/disclosure control must have an accessible name such as Expand / Collapse and expose aria-expanded.
• Enter/Space on the disclosure control toggles expansion only.
• Activating the Dashboard name/primary row opens View mode.
• Tree Left/Right keys should continue to collapse/expand according to the existing keyboard-tree model.
• Focus styling must make the disclosure control and Dashboard navigation target distinguishable.

Acceptance criteria

• Clicking only the disclosure chevron expands or collapses the Dashboard hierarchy.
• Clicking the Dashboard name opens that Dashboard in View mode.
• Name navigation preserves the current expansion state.
• Chevron activation does not navigate or rerun the Dashboard.
• Opening uses the stable Dashboard ID.
• The trailing menu remains isolated from both behaviours.
• Double-click does not cause duplicate route/history changes.
• Keyboard and screen-reader users can independently expand the hierarchy and open the Dashboard.
• Tests cover collapsed and expanded rows, active and inactive Dashboards, menu isolation, and repeated name activation.

Non-goals

• Changing panel/filter row interactions.
• Changing Dashboard View/Edit rendering.
• Moving or redesigning the trailing Dashboard action menu.
• Persisting expansion state in workspace data.

[BorisTyshkevich]

Absorbed into #429 and closed — owner decision (2026-07-27): #429 owns all
Dashboard-tree management and click operations.

Why this one had to merge rather than sequence

It is a direct collision, not just an adjacency. Both issues rewire the same
Dashboard row's event handling:

• Dashboard tree management: direct Dashboard and Panel actions #429 adds a trailing pencil to the Dashboard row and specifies "Dashboard
  row gets pencil only";
• this issue re-splits that row into chevron / name / trailing menu and
  describes the trailing control as a menu that "retains its existing Dashboard
  actions".

Those two descriptions of one row already disagree, and whichever shipped second
would have had to redo the other's wiring and re-test the same gesture matrix.

What carried over into #429

The full spec, in a new Dashboard row (revised) table plus requirements:
chevron expands only; name opens View by stable openDashboard({ dashboardId }),
never by title or position; Shift-click on the name keeps Edit; the trailing
action never navigates or expands; no duplicate history entry on double-click;
and the delayed single/double-click arbitration is retired for Dashboard rows
since expansion and navigation now have separate targets.

Keyboard/ARIA carried over intact: aria-expanded, Expand/Collapse accessible
names, Enter/Space toggling expansion only, Left/Right keeping the existing
keyboard-tree model, and focus styling distinguishing all three targets.

Your test list is now #429's "Dashboard row gestures (#472)" subsection, and
acceptance bullet "The Dashboard row's chevron, name and trailing action are
three independent targets, each keyboard-operable and separately announced".

Both your non-goals are retained in #429's own non-goals: the trailing menu is
not moved or redesigned as a control, and expansion state is not persisted in
workspace data. #429 also explicitly notes it revises #426's Dashboard-row
gestures — the line claiming "#426's navigation gestures remain unchanged" was
wrong once this landed, and is now corrected there.

Nothing dropped; closing as absorbed, not as rejected.