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/3-solutioning/check-implementation-readiness/workflow.md

@@ -52,4 +52,4 @@ Load and read full config from {project-root}/_bmad/bmm/config.yaml and resolve:
 
 ### 2. First Step EXECUTION
 
-Load, read the full file and then execute `{workflow_path}/steps/step-01-document-discovery.md` to begin the workflow.
+Load, read the full file and then execute `./step-01-document-discovery.md` to begin the workflow.