steg 2

README.md

@@ -17,11 +17,17 @@ authoritative for timing, odds, settlement, and analytics.
 - `backend/` Rust API and migrations
 - `contracts/` OpenAPI and localization contracts
 - `docs/` architecture, schema, and state-machine docs
+- `docs/conventions.md` Rust style notes
 - `infra/` local environment and deployment assets
 - `mobile/` native app scaffolds
 - `fixtures/` sample media and test data
 - `scripts/` helper automation
 
+## Coding Conventions
+
+- JSON-heavy Rust files should import `serde_json as json`
+- Prefer happy-path functions and early `let Some(...) = ... else { ... }` exits
+
 ## Status
 
 The repository has been initialized with the first planning and backend