Update README.md with test coverage badge

README.md

@@ -10,6 +10,7 @@
   <img src="https://img.shields.io/badge/Language-Rust-orange?style=flat-square" alt="Written in Rust" />
   <img src="https://img.shields.io/badge/Powered_by-Tauri_v2-grey?style=flat-square" alt="Tauri v2" />
   <img src="https://img.shields.io/badge/Status-Alpha-yellow?style=flat-square" alt="Alpha status" />
+  <img src="https://img.shields.io/badge/Tests-37-green?style=flat-square" alt="37 unit tests" />
   <img src="https://img.shields.io/github/v/release/spalencsar/deskify?label=Latest%20Release&style=flat-square" alt="Latest release" />
   <img src="https://img.shields.io/badge/License-MIT-green?style=flat-square" alt="MIT license" />
 </p>
@@ -102,7 +103,7 @@ Deskify intentionally does not aim to:
 - **Build model:** `deskify` compiles the wrapper locally on your machine
 - **Why this MVP design:** simpler debugging, isolated failures, low contributor complexity
 - **Tradeoff:** build time and distro-specific setup issues become user-facing
-- **Test coverage:** currently limited (core behavior is implemented, automated coverage is growing)
+- **Test coverage:** 37 unit tests covering desktop entry escaping, Tauri config generation, validation, Chromium backend, and app config serialization
 
 ### MVP Architecture (Today)