feat(viz-platform): complete Sprint 1 - plugin structure and tests

Sprint 1 - viz-platform Plugin completed (13/13 issues):
- Commands: 7 files (initial-setup, chart, dashboard, theme, theme-new, theme-css, component)
- Agents: 3 files (theme-setup, layout-builder, component-check)
- Documentation: README.md, claude-md-integration.md
- Tests: 94 tests passing (68-99% coverage)
- CHANGELOG updated with completion status

Closes: #178, #179, #180, #181, #182

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

plugins/viz-platform/commands/dashboard.md

@@ -0,0 +1,115 @@
+---
+description: Create a dashboard layout with the layout-builder agent
+---
+
+# Create Dashboard
+
+Create a dashboard layout structure with filters, grids, and sections.
+
+## Usage
+
+```
+/dashboard {template}
+```
+
+## 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
+```
+
+## Agent Mapping
+
+This command activates the **layout-builder** agent which orchestrates multiple tools:
+
+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
+
+## 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