Enable MMU for kernel isolation

[jserv]

Building upon the foundation established in Operating System in 1,000 Lines, implement memory management unit (MMU) functionality to introduce virtual memory addressing and protect the kernel from task-induced corruption. The current design utilizes a unified address space to optimize performance throughput. The enhancement should establish isolated address spaces that separate kernel memory from user tasks, leveraging MMU-based memory protection to prevent unauthorized memory access that could compromise system integrity or interfere with other software components.