feat(lexer): add type system keywords

Added four keywords for new type system:
- concept: Base type definition
- sub_concept: Enum/record sub-type definition
- concept_comparison: Compile-time enum mapping
- any: Universal type for dynamic contexts

Also added:
- CLAUDE.md with project instructions and commit guidelines
- Test coverage for new keywords
- Crate-level deny directives for unused variables and dead code

Fixed pre-existing clippy issues to pass pre-commit hooks.

src/lsp/hover.rs

@@ -39,13 +39,11 @@ pub fn get_hover_info(text: &str, line: usize, character: usize) -> Option<Hover
             }
 
             // Add the character offset (assuming UTF-8)
-            let mut char_count = 0;
-            for (byte_pos, _) in line_text.char_indices() {
+            for (char_count, (byte_pos, _)) in line_text.char_indices().enumerate() {
                 if char_count == character {
                     byte_offset += byte_pos;
                     break;
                 }
-                char_count += 1;
             }
             break;
         }
@@ -123,13 +121,11 @@ pub fn get_semantic_hover_info(doc: &Document, line: usize, character: usize) ->
                 return None;
             }
 
-            let mut char_count = 0;
-            for (byte_pos, _) in line_text.char_indices() {
+            for (char_count, (byte_pos, _)) in line_text.char_indices().enumerate() {
                 if char_count == character {
                     byte_offset += byte_pos;
                     break;
                 }
-                char_count += 1;
             }
             break;
         }
@@ -156,7 +152,7 @@ pub fn get_semantic_hover_info(doc: &Document, line: usize, character: usize) ->
     let word = target_ident?;
 
     // Look up the symbol in the name table
-    let symbol_info = doc.name_table.lookup(&[word.clone()])?;
+    let symbol_info = doc.name_table.lookup(std::slice::from_ref(&word))?;
 
     // Find the declaration in the AST
     for decl in &ast.declarations {