Initialize _header and _numValues members to safe defaults

Consistent with prior member initialization fixes across the library.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

Author: crayy8

rejistry++/src/HBIN.h

@@ -126,7 +126,7 @@ namespace Rejistry {
         HBIN(const HBIN &);
         HBIN& operator=(const HBIN &);
 
-        const REGFHeader * _header;
+        const REGFHeader * _header = NULL;
     };
 };
 

rejistry++/src/ValueListRecord.h

@@ -70,7 +70,7 @@ namespace Rejistry {
     private:
         static const uint16_t VALUE_LIST_OFFSET = 0x00;
 
-        uint32_t _numValues;
+        uint32_t _numValues = 0;
 
     protected:
         ValueListRecord() {};