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/skills/mcp-tools-reference.md

@@ -0,0 +1,159 @@
+# Viz-Platform MCP Tools Reference
+
+## Tool Categories
+
+| Category | Tools |
+|----------|-------|
+| DMC Validation | `list_components`, `get_component_props`, `validate_component` |
+| Charts | `chart_create`, `chart_configure_interaction`, `chart_export` |
+| Layouts | `layout_create`, `layout_add_filter`, `layout_set_grid`, `layout_set_breakpoints` |
+| Themes | `theme_create`, `theme_extend`, `theme_validate`, `theme_export_css`, `theme_list`, `theme_activate` |
+| Pages | `page_create`, `page_add_navbar`, `page_set_auth` |
+| Accessibility | `accessibility_validate_colors`, `accessibility_validate_theme`, `accessibility_suggest_alternative` |
+
+## DMC Validation Tools
+
+### list_components
+```python
+list_components(category=None)  # All components
+list_components(category="inputs")  # Filter by category
+```
+
+### get_component_props
+```python
+get_component_props(component="Button")
+```
+
+### validate_component
+```python
+validate_component(
+    component="Button",
+    props={"variant": "filled", "color": "blue"}
+)
+```
+
+## Chart Tools
+
+### chart_create
+```python
+chart_create(
+    chart_type="line",
+    data_ref="df_sales",
+    x="date",
+    y="revenue",
+    color=None,
+    title="Sales Over Time",
+    theme=None
+)
+```
+
+### chart_export
+```python
+chart_export(
+    figure=figure_json,
+    format="png",  # png, svg, pdf
+    width=1200,
+    height=800,
+    scale=2,
+    output_path=None
+)
+```
+
+## Layout Tools
+
+### layout_create
+```python
+layout_create(
+    name="my-dashboard",
+    template="sidebar"  # basic, sidebar, tabs, split
+)
+```
+
+### layout_add_filter
+```python
+layout_add_filter(
+    layout_ref="my-dashboard",
+    filter_type="dropdown",  # dropdown, date_range, slider, checkbox, search
+    options={}
+)
+```
+
+### layout_set_grid
+```python
+layout_set_grid(
+    layout_ref="my-dashboard",
+    cols=12,
+    spacing="md"
+)
+```
+
+### layout_set_breakpoints
+```python
+layout_set_breakpoints(
+    layout_ref="my-dashboard",
+    breakpoints={
+        "xs": {"cols": 1, "spacing": "xs"},
+        "sm": {"cols": 2, "spacing": "sm"},
+        "md": {"cols": 6, "spacing": "md"},
+        "lg": {"cols": 12, "spacing": "md"},
+        "xl": {"cols": 12, "spacing": "lg"}
+    },
+    mobile_first=True
+)
+```
+
+## Theme Tools
+
+### theme_create
+```python
+theme_create(
+    name="corporate",
+    primary_color="indigo",
+    color_scheme="light",
+    font_family="Inter, sans-serif",
+    heading_font_family=None,
+    border_radius="md",
+    spacing_scale=1.0,
+    colors=None
+)
+```
+
+### theme_extend
+```python
+theme_extend(
+    base_theme="dark",
+    name="dark-corporate",
+    overrides={"primary_color": "indigo"}
+)
+```
+
+### theme_validate
+```python
+theme_validate(theme_name="corporate")
+```
+
+### theme_export_css
+```python
+theme_export_css(theme_name="corporate")
+```
+
+### theme_activate
+```python
+theme_activate(theme_name="dark")
+```
+
+## Accessibility Tools
+
+### accessibility_validate_colors
+```python
+accessibility_validate_colors(
+    colors=["#228be6", "#40c057", "#fa5252"],
+    check_types=["deuteranopia", "protanopia", "tritanopia"],
+    min_contrast_ratio=4.5
+)
+```
+
+### accessibility_validate_theme
+```python
+accessibility_validate_theme(theme_name="corporate")
+```