refactor(viz-platform): extract skills and slim commands

Extract shared knowledge from 10 commands into 7 reusable skills:
- mcp-tools-reference.md: All viz-platform MCP tool signatures
- theming-system.md: Theme tokens, CSS variables, color palettes
- accessibility-rules.md: WCAG contrast, color-blind safe palettes
- dmc-components.md: DMC categories, validation, common props
- responsive-design.md: Breakpoints, mobile-first, grid config
- chart-types.md: Plotly chart types, export formats, resolution
- layout-templates.md: Dashboard templates, filter types

All commands now reference skills via "Skills to Load" section.
Commands reduced from 1396 lines total to 427 lines (69% reduction).

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

plugins/viz-platform/commands/dashboard.md

@@ -4,19 +4,19 @@ description: Create a dashboard layout with the layout-builder agent
 
 # Create Dashboard
 
+## Skills to Load
+- skills/mcp-tools-reference.md
+- skills/layout-templates.md
+
 ## Visual Output
 
-When executing this command, display the plugin header:
-
 ```
-┌──────────────────────────────────────────────────────────────────┐
-│  🎨 VIZ-PLATFORM · Dashboard Builder                              │
-└──────────────────────────────────────────────────────────────────┘
++------------------------------------------------------------------+
+|  VIZ-PLATFORM - Dashboard Builder                                |
++------------------------------------------------------------------+
 ```
 
-Then proceed with the dashboard creation.
-
-Create a dashboard layout structure with filters, grids, and sections.
+Create a dashboard layout with filters, grids, and sections.
 
 ## Usage
 
@@ -26,102 +26,16 @@ Create a dashboard layout structure with filters, grids, and sections.
 
 ## Arguments
 
-- `template` (optional): Layout template - one of: basic, sidebar, tabs, split
-
-## Examples
-
-```
-/dashboard              # Interactive layout builder
-/dashboard basic        # Simple single-column layout
-/dashboard sidebar      # Layout with sidebar navigation
-/dashboard tabs         # Tabbed multi-page layout
-/dashboard split        # Split-pane layout
-```
+- `template` (optional): basic, sidebar, tabs, split
 
 ## Agent Mapping
 
-This command activates the **layout-builder** agent which orchestrates multiple tools:
+Activates **layout-builder** agent which orchestrates:
+- `layout_create` - Create base layout structure
+- `layout_add_filter` - Add filter components
+- `layout_set_grid` - Configure responsive grid
 
-1. `layout_create` - Create the base layout structure
-2. `layout_add_filter` - Add filter components (dropdowns, date pickers)
-3. `layout_set_grid` - Configure responsive grid settings
-4. `layout_add_section` - Add content sections
+## Related Commands
 
-## Workflow
-
-1. **User invokes**: `/dashboard sidebar`
-2. **Agent asks**: What is the dashboard purpose?
-3. **Agent asks**: What filters are needed?
-4. **Agent creates**: Base layout with `layout_create`
-5. **Agent adds**: Filters with `layout_add_filter`
-6. **Agent configures**: Grid with `layout_set_grid`
-7. **Agent returns**: Complete layout structure
-
-## Templates
-
-### Basic
-Single-column layout with header and content area.
-```
-┌─────────────────────────────┐
-│          Header             │
-├─────────────────────────────┤
-│                             │
-│          Content            │
-│                             │
-└─────────────────────────────┘
-```
-
-### Sidebar
-Layout with collapsible sidebar navigation.
-```
-┌────────┬────────────────────┐
-│        │       Header       │
-│  Nav   ├────────────────────┤
-│        │                    │
-│        │      Content       │
-│        │                    │
-└────────┴────────────────────┘
-```
-
-### Tabs
-Tabbed layout for multi-page dashboards.
-```
-┌─────────────────────────────┐
-│          Header             │
-├──────┬──────┬──────┬────────┤
-│ Tab1 │ Tab2 │ Tab3 │        │
-├──────┴──────┴──────┴────────┤
-│                             │
-│       Tab Content           │
-│                             │
-└─────────────────────────────┘
-```
-
-### Split
-Split-pane layout for comparisons.
-```
-┌─────────────────────────────┐
-│          Header             │
-├──────────────┬──────────────┤
-│              │              │
-│    Left      │    Right     │
-│    Pane      │    Pane      │
-│              │              │
-└──────────────┴──────────────┘
-```
-
-## Filter Types
-
-Available filter components:
-- `dropdown` - Single/multi-select dropdown
-- `date_range` - Date range picker
-- `slider` - Numeric range slider
-- `checkbox` - Checkbox group
-- `search` - Text search input
-
-## Output
-
-Returns a layout structure that can be:
-- Used with page tools to create full app
-- Rendered as a Dash layout
-- Combined with chart components
+- `/breakpoints {layout}` - Configure responsive breakpoints
+- `/chart {type}` - Add charts to layout