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

.agent/workflows/bmad/bmad-bmm-workflows-create-excalidraw-dataflow.md

@@ -0,0 +1,13 @@
+---
+description: 'Create data flow diagrams (DFD) in Excalidraw format'
+---
+
+IT IS CRITICAL THAT YOU FOLLOW THESE STEPS - while staying in character as the current agent persona you may have loaded:
+
+<steps CRITICAL="TRUE">
+1. Always LOAD the FULL @_bmad/core/tasks/workflow.xml
+2. READ its entire contents - this is the CORE OS for EXECUTING the specific workflow-config @_bmad/bmm/workflows/excalidraw-diagrams/create-dataflow/workflow.yaml
+3. Pass the yaml path _bmad/bmm/workflows/excalidraw-diagrams/create-dataflow/workflow.yaml as 'workflow-config' parameter to the workflow.xml instructions
+4. Follow workflow.xml instructions EXACTLY as written to process and follow the specific workflow config and its instructions
+5. Save outputs after EACH section when generating any documents from templates
+</steps>