XDB v1.4.1 - resolve SIGSEGV and memory corruption

[1.4.1] - 2026-01-31

Fixed (Stability & Memory Integrity)

• Atomic Insert (Deep Copy): Resolved Use-After-Free memory corruption by implementing cJSON_Duplicate in the db_insert function. The database now maintains full memory ownership, isolated from the network layer request lifecycle.
• Safe Detach-Append Strategy: Replaced destructive in-place replacement with a Detach & Append strategy for update operations. This ensures internal Linked List pointer integrity during high-concurrency access.
• Thread-Safe Iteration: Replaced standard iteration macros with manual pointer navigation to prevent race conditions when the collection structure is modified by concurrent threads.
• SIGSEGV Prevention: Eliminated the primary cause of Segmentation Faults in the get_object_item function, previously triggered by dangling pointer access.