feat: add rendering-primitives crate, share non_import_rels across renderers

crates/adapters/rendering-primitives/src/lib.rs

@@ -0,0 +1,11 @@
+use archlens_domain::{Relationship, RelationshipKind};
+
+/// Returns an iterator over all relationships except those with kind `Import`.
+pub fn non_import_rels(rels: &[Relationship]) -> impl Iterator<Item = &Relationship> {
+    rels.iter().filter(|r| r.kind() != RelationshipKind::Import)
+}
+
+/// Replaces `::`, `-`, `.`, and space with `_`.
+pub fn sanitize_identifier(name: &str) -> String {
+    name.replace("::", "_").replace(['-', '.', ' '], "_")
+}