fix(ui): theme WorkflowEditor for dark mode
Replace all hardcoded gray-*/white Tailwind classes with semantic CSS
variable tokens (bg-surface, text-content, border-border-default, etc.)
so the page respects dark/light mode correctly.
- Sidebar, header bar, toolbar: bg-surface + border-border-default
- Node cards: bg-surface + border-accent (selected) / border-border-default
- ConfigSidepanel: bg-surface, text-content-secondary labels
- NewWorkflowModal: bg-surface, border-border-default inputs, accent buttons
- Workflow list items: bg-accent-light highlight for selected, hover:bg-surface-hover
- Empty state icon: text-content-muted
- ReactFlow: colorMode prop tied to useThemeStore (dark/light)
- Background: removed hardcoded #e5e7eb dot color (uses ReactFlow colorMode)
- All blue-600 buttons → bg-accent / hover:bg-accent-hover
Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>
Hartmut
df02067687