feat(ast): add type system declaration nodes

Added AST structures for new type system:
- ConceptDecl: Base type definition
- SubConceptDecl: Enum or record subtype with SubConceptKind
- ConceptComparisonDecl: Compile-time enum mapping
- ConceptMapping: Individual mapping entry

Added Declaration enum variants and stubs throughout codebase
for LSP, resolve, and semantic analysis modules.

src/resolve/convert.rs

@@ -98,6 +98,11 @@ pub fn convert_file_with_all_files(
                 // Use declarations are handled during name resolution, not
                 // conversion
             },
+            | ast::Declaration::Concept(_) |
+            ast::Declaration::SubConcept(_) |
+            ast::Declaration::ConceptComparison(_) => {
+                // TODO: Implement conversion for type system declarations
+            },
         }
     }
 

src/resolve/names.rs

@@ -139,6 +139,10 @@ impl NameTable {
                 | Declaration::Location(l) => (l.name.clone(), DeclKind::Location, l.span.clone()),
                 | Declaration::Species(s) => (s.name.clone(), DeclKind::Species, s.span.clone()),
                 | Declaration::Enum(e) => (e.name.clone(), DeclKind::Enum, e.span.clone()),
+                | Declaration::Concept(_) |
+                Declaration::SubConcept(_) |
+                Declaration::ConceptComparison(_) => continue, /* TODO: Implement name resolution
+                                                                * for type system */
             };
 
             // For now, qualified path is just the name

src/resolve/references.rs

@@ -191,6 +191,11 @@ fn find_references_in_declaration(
         | Declaration::Use(_) => {
             // Use statements are handled separately
         },
+        | Declaration::Concept(_) |
+        Declaration::SubConcept(_) |
+        Declaration::ConceptComparison(_) => {
+            // TODO: Implement reference finding for type system
+        },
     }
 
     refs