Merge branch 'develop' into mvadari/rearch/account

docs/build/environment.md

@@ -109,3 +109,32 @@ Install CMake with Homebrew too:
 ```
 brew install cmake
 ```
+
+## Clang-tidy
+
+Clang-tidy is required to run static analysis checks locally (see [CONTRIBUTING.md](../../CONTRIBUTING.md)).
+It is not required to build the project. Currently this project uses clang-tidy version 21.
+
+### Linux
+
+LLVM 21 is not available in the default Debian 12 (Bookworm) repositories.
+Install it using the official LLVM apt installer:
+
+```
+wget https://apt.llvm.org/llvm.sh
+chmod +x llvm.sh
+sudo ./llvm.sh 21
+sudo apt install --yes clang-tidy-21
+```
+
+Then use `run-clang-tidy-21` when running clang-tidy locally.
+
+### macOS
+
+Install LLVM 21 via Homebrew:
+
+```
+brew install llvm@21
+```
+
+Then use `run-clang-tidy` from the LLVM 21 Homebrew prefix when running clang-tidy locally.