fix: unify theme system - fix theme switching persistence

- Unified localStorage key to 'theme-preference' across all components
- Fixed header.tsx using wrong localStorage key ('theme' instead of 'theme-preference')
- Added localStorage hybrid persistence for instant theme changes
- Removed router.refresh() which was causing stale data revert
- Replaced Blue theme with Sepia
- Consolidated auth() calls to prevent race conditions
- Updated UserSettingsData types to include all themes

_bmad/bmm/workflows/excalidraw-diagrams/create-diagram/instructions.md

@@ -1,7 +1,7 @@
 # Create Diagram - Workflow Instructions
 
 ```xml
-<critical>The workflow execution engine is governed by: {project_root}/_bmad/core/tasks/workflow.xml</critical>
+<critical>The workflow execution engine is governed by: {project-root}/_bmad/core/tasks/workflow.xml</critical>
 <critical>You MUST have already loaded and processed: {installed_path}/workflow.yaml</critical>
 <critical>This workflow creates system architecture diagrams, ERDs, UML diagrams, or general technical diagrams in Excalidraw format.</critical>