docs: map existing codebase with PAUL

- stack.md - PrestaShop 1.7.x, PHP, Smarty, SCSS, modules
- architecture.md - MVC + hooks, override mechanism, CQRS in src/
- structure.md - Directory layout, key file locations
- conventions.md - PHP/Smarty/SCSS/JS conventions, PS patterns
- testing.md - No automated tests in custom modules
- integrations.md - Allegro, Empik, BaseLinker, shipping, payments
- concerns.md - Override fragility, EOL risk, missing CI/CD
- db_schema.md - Custom tables, modified core tables

Co-Authored-By: Claude <noreply@anthropic.com>

.paul/PROJECT.md

@@ -0,0 +1,30 @@
+# Project: interblue.pl
+
+## Description
+Bieżące poprawki i rozwój istniejącego sklepu PrestaShop 1.7.x — elektronika oświetleniowa B2C.
+
+## Core Value
+Klienci B2C mogą kupić elektronikę oświetleniową online.
+
+## Requirements
+
+### Must Have
+- [To be defined during planning]
+
+### Should Have
+- [To be defined during planning]
+
+### Nice to Have
+- [To be defined during planning]
+
+## Constraints
+- PrestaShop 1.7.x — zmiany muszą być kompatybilne z tą wersją
+- Deployment przez FTP (brak CI/CD)
+- Cache PrestaShop musi być czyszczony ręcznie po zmianach PHP/override
+
+## Success Criteria
+- Klienci B2C mogą kupić elektronikę oświetleniową online
+- [To be refined during planning]
+
+---
+*Created: 2026-04-27*