* refactor(tui): port to charm v2
bumped bubbletea, lipgloss, bubbles, wish, and huh to v2. Mostly
mechanical chur, new import paths, vewport getter/setter api, view()
returns tea.view now, huh.theme became an interface so the theme package
needed a small reshape. Render plumbing is gone (no more lipgloss.Render
field on the Model or MakeRenderer in main.go). All pages still work
over ssh. setting up for the refund composer next
* style(tui): gofmt main.go and menu.go
added dedicated *Switch() methods (ShopSwitch, CartSwitc, AccountSwitch, ...) for page transitions and remove the catch-all resetPageState(). Each switch owns its pages zero-init, viewport setup, and async data fetching
prices stored as float64 could lead to rounding errors when converting to cents for stripe (19.99 * 100 = 1998.99... truncating to 1998). canged Coffee.Price to int, storing cents directly. Updated the seed data, fallback products, API handlers, and all TUI display code to be in sync with this change.
