refactor: rename command files for namespace consistency

BREAKING CHANGE: All generic command names now prefixed with plugin namespace.
See CHANGELOG.md v7.0.0 for complete rename map.

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

plugins/viz-platform/commands/viz-theme-new.md

@@ -0,0 +1,41 @@
+---
+description: Create a new custom theme with design tokens
+---
+
+# Create New Theme
+
+## Skills to Load
+- skills/mcp-tools-reference.md
+- skills/theming-system.md
+
+## Visual Output
+
+```
++------------------------------------------------------------------+
+|  VIZ-PLATFORM - New Theme                                        |
++------------------------------------------------------------------+
+```
+
+Create a new custom theme with specified design tokens.
+
+## Usage
+
+```
+/theme-new {name}
+```
+
+## Arguments
+
+- `name` (required): Name for the new theme
+
+## Tool Mapping
+
+```python
+theme_create(name="corporate", primary_color="indigo", color_scheme="light", font_family="Inter")
+theme_validate(theme_name="corporate")
+```
+
+## Related Commands
+
+- `/theme {name}` - Apply a theme
+- `/theme-css {name}` - Export theme as CSS