scale it sane way:
src/
app/
layout.tsx
page.tsx # notes listing
archive/
page.tsx
note/
[id]/
page.tsx
components/
ui/ # generic UI (button, modal, input)
notes/ # specific to notes features
hooks/ # e.g. useLocalStorage, useTheme
store/ # Zustand stores
lib/ # utils (filtering, persistence helpers)
types/ # shared TS types
styles/ # Tailwind/global CSS overrides
data/ # seed or mock data (optional)