Cursor rule

1---
2description: General context for the Stock Portfolio Web project
3alwaysApply: true
4---
5 
6# Stock Portfolio Web - Overview
7 
8A pure TypeScript SPA (no React/Vue/Angular) for calculating taxes on stock operations (E*Trade RSU/ESPP).
9 
10## Stack
11 
12- **Runtime**: TypeScript 5.9, ES2020
13- **Build**: Vite 7
14- **Testing**: Vitest 4 with V8 coverage
15- **Linting**: ESLint + Prettier
16- **Main dependency**: pdfjs-dist (PDF parsing)
17- **External API**: BCB PTAX (exchange rates)
18 
19## Layer Structure (Clean Architecture)
20 
21```
22src/
23├── domain/          → Pure entities and services (no external dependencies)
24├── application/     → Use cases and interfaces (contracts)
25├── infrastructure/  → Repositories, APIs, concrete utilities
26└── presentation/    → UI, formatters, HTML builders
27```
28 
29## Fundamental Rules
30 
31- Never import from `infrastructure/` or `presentation/` inside `domain/`
32- Use cases orchestrate the flow, they never contain domain logic
33- All external API communication belongs in `infrastructure/`
34- The `presentation/` layer never accesses repositories directly
35