init: archlens — architecture diagram generator

Hex arch + DDD, tree-sitter parsing, Mermaid/ASCII output.
Supports Rust + Python. 92 tests. CI, diff, --check for staleness detection.

crates/domain/tests/analysis_warning_tests.rs

@@ -0,0 +1,21 @@
+use archlens_domain::{AnalysisWarning, FilePath};
+
+#[test]
+fn warning_carries_location_and_message() {
+    let warning = AnalysisWarning::new(
+        FilePath::new("src/broken.rs").unwrap(),
+        42,
+        "could not parse struct definition",
+    )
+    .unwrap();
+
+    assert_eq!(warning.file_path().as_str(), "src/broken.rs");
+    assert_eq!(warning.line(), 42);
+    assert_eq!(warning.message(), "could not parse struct definition");
+}
+
+#[test]
+fn warning_rejects_empty_message() {
+    let result = AnalysisWarning::new(FilePath::new("src/broken.rs").unwrap(), 1, "");
+    assert!(result.is_err());
+}