Bulk editing for multi-selected tasks

[kitikonti]

Description

When multiple tasks are selected, allow editing shared properties for all selected tasks at once (bulk edit).

Candidate Properties for Bulk Edit

• Color - Change color of all selected tasks (high value)
• Progress - Set progress for all selected tasks
• Type - Convert all selected to task/milestone
• Assignee - (future, if added)

Notes

• Not all columns make sense for bulk editing (e.g., name, dates are unique per task)
• UX concept needed: inline editing vs. a bulk edit panel/popover
• This feature is not fully designed yet — needs a concept phase before implementation

[kitikonti]

Context from #2 discussion

During the implementation of indent/outdent for active cell selection (#2), we evaluated multi-cell selection (selecting individual cells across different rows/columns, Excel-style) and rejected it — there are virtually no use cases for it in a Gantt chart context.

This is relevant for the UX concept here: inline multi-cell editing is off the table as an approach. Bulk editing should instead use a dedicated UI like a toolbar action, context menu, or popover/panel when multiple rows are selected.