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/config_tests.rs

@@ -0,0 +1,37 @@
+use archlens_domain::{AnalysisConfig, DiagramLevel, OutputConfig};
+
+#[test]
+fn analysis_config_has_sensible_defaults() {
+    let config = AnalysisConfig::default();
+    assert!(config.excludes().is_empty());
+    assert_eq!(config.level(), DiagramLevel::Module);
+    assert!(config.module_mappings().is_empty());
+}
+
+#[test]
+fn analysis_config_with_excludes() {
+    let config =
+        AnalysisConfig::default().with_excludes(vec!["tests/".to_string(), "vendor/".to_string()]);
+
+    assert_eq!(config.excludes().len(), 2);
+}
+
+#[test]
+fn output_config_has_sensible_defaults() {
+    let config = OutputConfig::default();
+    assert!(!config.split_by_module());
+    assert!(config.output_path().is_none());
+}
+
+#[test]
+fn output_config_with_split() {
+    let config = OutputConfig::default().with_split_by_module(true);
+    assert!(config.split_by_module());
+}
+
+#[test]
+fn all_diagram_levels_exist() {
+    let _project = DiagramLevel::Project;
+    let _module = DiagramLevel::Module;
+    let _type_level = DiagramLevel::Type;
+}