feat: Add complete PHP language support with trait handling and property extraction

Addresses PHP traits extracted as classes, missing class properties, skipped constants, and invisible trait usage. Adds classifyClassNode to distinguish traits from classes, fixes property extraction for PHP's property_element AST structure (added 4,366 field nodes), and adds visitNode hook for class constants and trait use declarations (increased trait edges from 636 to 1,514). Also improves Liquid schema name handling and file path reference resolution. Verified against Laravel codebase.

src/resolution/types.ts

@@ -39,7 +39,7 @@ export interface ResolvedRef {
   /** Confidence score (0-1) */
   confidence: number;
   /** How it was resolved */
-  resolvedBy: 'exact-match' | 'import' | 'qualified-name' | 'framework' | 'fuzzy' | 'instance-method';
+  resolvedBy: 'exact-match' | 'import' | 'qualified-name' | 'framework' | 'fuzzy' | 'instance-method' | 'file-path';
 }
 
 /**