Build helper tests

Live under crates/canopen-eds-build/tests/.

Test Case: Builder writes a parseable Rust file to OUT_DIR TEST_0650
status: open
verifies: REQ_0760, REQ_0761

Test crate driven by a fixture EDS set runs Builder::new().glob(...).backend(default).out_file( "devices.rs").build() in a tempfile-backed OUT_DIR. Asserts the file exists, is non-empty, and parses with syn::parse_file (catches malformed token streams).
Test Case: cargo rerun-if-changed emitted per EDS input TEST_0651
status: open
verifies: REQ_0762

Capture Builder::build()’s stdout. For an N-file glob, assert exactly N + 1 cargo:rerun-if-changed= lines are present (one per EDS file + one for the build script itself).
Test Case: Output passes prettyplease formatting TEST_0652
status: open
verifies: REQ_0763

The generated devices.rs file is line-wrapped, and re-running prettyplease::unparse on the file produces a byte-identical output (idempotent formatter pass).
Test Case: Parser warnings surface as cargo:warning lines TEST_0653
status: open
verifies: REQ_0764

Drive the builder against a fixture set including the liberal-quirk EDS from Liberal-quirk parsing emits... (TEST_0615). Capture stdout, assert that one cargo:warning= line appears per quirk warning raised by the parser, and that the build still exits Ok.