Add budget module and customizable navigation settings

[31b4]

Summary

• Implemented the new budget feature with dedicated components, DTOs, service/repository, and API routes so budgets can be created per account/category and render cleanly in the client UI
• Added the Settings section allowing users to toggle visibility of Dashboard, Analytics, Investments, Recurring, and Budget menus so the navbar stays tailored to their preferences
• Ensured deploy/migration scripts reflect the new budget resources and surface clearer status (migration log fixes still outstanding)

Testing

• Not run (not requested)