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/src/value_objects/source/source_file.rs

@@ -0,0 +1,21 @@
+use crate::{FilePath, Language};
+
+#[derive(Debug, Clone)]
+pub struct SourceFile {
+    path: FilePath,
+    language: Language,
+}
+
+impl SourceFile {
+    pub fn new(path: FilePath, language: Language) -> Self {
+        Self { path, language }
+    }
+
+    pub fn path(&self) -> &FilePath {
+        &self.path
+    }
+
+    pub fn language(&self) -> Language {
+        self.language
+    }
+}