* fix: check PATH for rust-analyzer before common locations, with functionality validation
Fixes#800 - rust-analyzer fails if rustup is not installed even when
rust-analyzer exists in PATH (e.g. NixOS, distro packages).
Changes:
- Move PATH check (shutil.which) before common location fallbacks
- Add _is_rust_analyzer_functional() to validate PATH-found binaries
by running --version, catching broken rustup proxy symlinks
- Add tests for Nix PATH detection and broken proxy skip scenarios
* fix: make test_skip_broken_rustup_proxy_in_path work on Windows
The test used hardcoded Unix paths (/usr/bin/rust-analyzer) and
os.path.expanduser("~/.cargo/bin/rust-analyzer") which doesn't
include the .exe extension. On Windows, the production code builds
common paths using pathlib with "rust-analyzer.exe", so the mock
paths never matched, causing RuntimeError instead of finding the
cargo fallback.
Use platform-appropriate paths: on Windows, use .exe extension and
pathlib.Path.home() to match how the production code constructs paths.
---------
Co-authored-by: VoidChecksum <Admin@CyberNord>
Youcef Hanaia