Local development

git clone <repo>
cd <project-folder>
npm install

POSTGRES_USER=...
POSTGRES_PASSWORD=...
POSTGRES_DB=...
CLOUD_SQL_INSTANCE_CONNECTION_NAME=...
GOOGLE_SERVICE_ACCOUNT_BASE64=...

npm run dev          # Dev server on http://localhost:3000
npm run build        # Production build (use to verify TypeScript)
npm run lint         # ESLint (flat config)
npm start            # Run the production build

npx next dev --port 3001

src/
├── app/                     # Next.js App Router routes
│   ├── api/                 # API route handlers
│   ├── (pages)/             # User-facing pages
│   └── layout.tsx           # Root layout with FloatingNav
├── components/
│   ├── dashboard/           # Domain components
│   └── ui/                  # Radix-based primitives
├── hooks/
│   └── useFleet.ts          # React Query hooks
├── lib/
│   ├── api.ts               # Typed fetch helpers
│   ├── db/                  # Postgres connection + table names
│   ├── models/              # TypeScript interfaces
│   ├── services/            # Business logic (FleetService, etc.)
│   └── utils/               # Calculators (CII, FuelEU, ports, Excel)
└── contexts/                # YearContext, VesselContext

import { calculateCII } from '@/lib/utils/ciiCalculator'