feat: timeline multi-select, demand popover, resource hover card, merged tooltips, dark mode fixes
Major timeline enhancements:
- Right-click drag multi-selection with floating action bar (batch delete/assign)
- DemandPopover for demand strip details (replaces broken "Loading" modal)
- ResourceHoverCard on name hover showing skills, rates, role, chapter
- Merged heatmap+vacation tooltips into unified TimelineTooltip component
- Fixed overbooking blink animation (date normalization, z-index ordering)
- Fixed dark mode sticky column bleed-through in project view
- System roles admin page, notification task management, performance review docs
Co-Authored-By: claude-flow <ruv@ruv.net>
Hartmut
ddec3a927a