Refactor workweek presets management architecture

Introduces dedicated WorkweekPresetsManager to improve code organization and reduce coupling

Separates concerns by moving workweek preset logic from ViewManager
Implements event-driven CSS synchronization
Removes code duplication in configuration and CSS property updates

Enhances maintainability and testability of UI component interactions

.claude/settings.local.json

@@ -12,7 +12,8 @@
       "Bash(npm test)",
       "Bash(cat:*)",
       "Bash(npm run test:run:*)",
-      "Bash(npx tsc)"
+      "Bash(npx tsc)",
+      "Bash(npx tsc:*)"
     ],
     "deny": []
   }